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>> [Review: Quiz 1]

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[Ali Nahm, Oreoluwa Barbarinsa, Lucas Freitas, Rob Bowden] [Chuo Kikuu cha Harvard]

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[Hii ni CS50.] [CS50.TV]

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[Lucas Freitas] Karibu kila mtu. Hii ni mapitio kwa jaribio 1.

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Tu kama Kanusho, hii ni - I mean, tunakwenda kujaribu kufunika

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vifaa kama iwezekanavyo, lakini hiyo haina maana kwamba

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tunakwenda cover yote ya mambo ambayo yanaweza kuwa katika jaribio 1.

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Hivyo kuwa na uhakika pia kuangalia katika hotuba, sehemu, kila kitu kuwa unaweza.

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Quiz 1 ni kwenda kuwa juu ya Jumatano, Jumatano ijayo.

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Hivyo kuwa na uhakika kujifunza. Ni kwenda kuwa, pretty much, kama jaribio la kwanza

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kuhusu muundo wake, lakini pengine ni kwenda kuwa ngumu sana.

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Kwa uchache, mwaka jana wakati mimi alichukua 50, nilifikiri ilikuwa vigumu sana.

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Hivyo utafiti mengi.

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>> Mimi nina kwenda kufidia miundo data na Huffman coding.

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Hili ni jambo ambalo mengi ya watu wanadhani ni tata,

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lakini mimi nina kwenda kujaribu kufanya hivyo kama rahisi kama iwezekanavyo.

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Awali ya yote, nini tunataka nyie kujua kwa jaribio 1 ni kwa

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kuelewa maelezo dhana ya kila data miundo kwamba mimi nina kwenda sasa.

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Hiyo ina maana kwamba huna kwa kweli

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kutekeleza meza hash katika jaribio yako 1.

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Hatutaki wewe kutekeleza yote hash meza, labda tutaweza kujaribu

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kufanya kutekeleza baadhi ya majukumu,

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shughuli ya kawaida, lakini sisi siyo kwenda kufanya kutekeleza kila kitu.

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Hivyo ni muhimu kwamba kuelewa dhana nyuma ya kila muundo data

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na pia kwamba una uwezo na kanuni katika C,

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tu shughuli ya kawaida wao na kwa kila muundo data.

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Na pia kuwa na uwezo wa kupitia kuyatumia na structs,

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kwa sababu wao kuonekana mengi katika miundo haya data.

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>> Kwanza, wanaohusishwa orodha. Orodha wanaohusishwa ni kweli ni sawa na arrays,

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lakini tofauti kati ya orodha wanaohusishwa na safu,

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kwanza ya yote, ni kwamba orodha wanaohusishwa ina rahisi sana ukubwa,

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wakati katika arrays una ama kuchagua ukubwa kubwa sana kwa safu,

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ili kujua kwamba wewe ni kwenda kuwa na uwezo wa kuhifadhi data yako yote katika safu,

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au una kutumia malloc kuwa na urefu rahisi wa safu.

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Katika orodha wanaohusishwa ni rahisi sana kupata tu mambo zaidi,

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kuweka mambo zaidi katika orodha wanaohusishwa au kuondoa vipengele.

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Na kwa kweli, kama wewe hawataki orodha wanaohusishwa na kutatuliwa,

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unaweza kutafuta na kuondoa vipengele katika wakati mara kwa mara,

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hivyo O (1) wakati, hivyo ni rahisi sana.

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Wewe tu kuwa makini daima kumbuka malloc na bure nodes,

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kwa sababu tu kama huna, itabidi uvujaji kumbukumbu.

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Orodha hiyo wanaohusishwa - ufafanuzi wa node ni kama yale tuna haki ya huko.

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Mimi kuweka int n, lakini unaweza kuhifadhi data yoyote unataka.

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Hivyo kama wewe unataka kuhifadhi kamba, ni nzuri.

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Kama unataka kuhifadhi struct, ni nzuri, mara mbili, chochote unataka.

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Mimi tu ya kuweka int n kwa mifano hapa.

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Na una pointer kwa node ijayo.

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Kwa hiyo, kimsingi, orodha wanaohusishwa ina baadhi ya data, na kisha inaelekeza katika node ijayo.

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Kama ni hiki mwisho katika orodha wanaohusishwa, ni kwenda kwa uhakika na null.

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Hivyo hii ni mfano wa orodha wanaohusishwa.

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>> Sawa, hivyo sasa hebu angalia nini tunapaswa kufanya kama nataka kuingiza kipengele katika orodha wanaohusishwa.

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Kwanza, kuingiza kazi itakuwa ya aina utupu

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kwa sababu sitaki kurudi kitu chochote.

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Na mimi nina kwenda kuchukua int kama hoja,

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kwa sababu Mimi nataka kujua nini nataka kuingiza.

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Basi nini Jambo la kwanza mimi wanapaswa kufanya nini? Naam, mimi lazima malloc juu ya newnode,

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hivyo kwamba ni mstari wa kwanza.

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Mimi nina kujenga tu nodi mpya kuweka katika orodha wanaohusishwa.

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Hivyo naweza kufanya nini? Vizuri, tunajua kwamba katika utekelezaji wa orodha wanaohusishwa wetu

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darasani, sisi daima kuweka kichwa kama variable kimataifa.

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Hivyo nini tunaweza kufanya ni kubadilisha kichwa.

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Mimi siwezi kufanya node hii mpya kuwa mkuu mpya,

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na ni kwenda kwa uhakika na kichwa uliopita.

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Jinsi gani tunaweza kufanya hivyo? Jambo la kwanza mimi kufanya

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ni mabadiliko 'n' katika node mpya ya thamani,

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ambayo ilipitishwa kufanya kazi.

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Kisha ni newnode ya pili ni kwenda kuwa kichwa.

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kichwa ni kwenda kuwa newnode. Hivyo ni pretty rahisi.

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Kwa ajili ya kufuta node, tunaweza kufanya hivyo kama -

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Njia moja tunaweza kufanya hivyo ni kusema,

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sawa, kama nilitaka kufuta, kwa mfano, 3,

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nini mimi naweza kufanya ni uhakika tu node uliopita

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kwa node ya pili ya 3.

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Hivyo napenda tu kufanya kitu kama hicho.

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Lakini ni tatizo na kufanya hivyo ni nini?

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Nina kumbukumbu leak, hivyo mimi si kupata namba 3 tena.

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tatizo na hilo ni kwamba mimi si kwenda kuwa na uwezo wa bure kwamba nodi.

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Mimi naenda kuwa na kumbukumbu leak na (yasiyo na) ni kwenda chuki yangu.

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Hivyo badala ya kufanya hivyo, mimi lazima pengine na pointer muda.

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Basi, mimi kuweka temp. Ni kwenda kwa uhakika na nodi kwamba mimi unataka kufuta.

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Na kisha naweza kusogeza nodes uliopita kwa uhakika node ijayo

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ya nodi kwamba mimi unataka kufuta.

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Na hatimaye, siwezi bure pointer.

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Je nina bure pointer kwamba mimi umba hapo?

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Sina, kwa sababu tu -

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Tofauti ni kwamba node hii iliundwa kwa kutumia malloc,

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hivyo ni katika chungu, wakati huu moja mara tu alitangaza kama NULL kubadili katika stack.

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Hivyo sina bure yake.

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>> Sawa. Hivyo sasa hebu majadiliano juu ya mwingi.

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Mwingi ni pretty moja kwa moja.

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Sisi tulikuwa mwingi na foleni katika darasa kwa kutumia arrays tu,

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lakini unapaswa kuwa familiar - tu kuwa na ufahamu

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kwamba unaweza pia kufanya mwingi katika foleni kutumia orodha wanaohusishwa pia.

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Hivyo kama una safu, nini itakuwa stack?

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stack, kwanza, itakuwa na kuwa na ukubwa.

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Una kuhifadhi nini ni ukubwa wa stack kwamba una haki sasa.

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Na pia ingekuwa safu, katika kesi hii ya idadi,

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lakini kama unataka, inaweza kuwa safu

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ya masharti, safu ya struct, kitu chochote ambacho unataka kuhifadhi.

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Kuhusu stack: Tofauti kati ya stack na orodha wanaohusishwa

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ni kwamba katika stack wewe tu na upatikanaji wa hiki mwisho kwamba ilikuwa kuweka katika stack.

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Ni wito mwisho, kwanza nje.

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Tu kama wewe na stack ya trays,

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kama wewe kuweka tray juu ya stack,

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una kuondoa kwamba tray kwanza kuwa na upatikanaji wa trays nyingine.

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Ni kitu kimoja na mwingi ni.

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Hivyo kama nataka, kwa mfano, kuongeza kipengele kwa stack, nifanye nini?

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Ni wito kushinikiza, na ni pretty moja kwa moja.

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Jambo la kwanza kufanya ni kuangalia kama kawaida ya stack

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si mkuu au sawa na uwezo wa stack.

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Kwa sababu kama wewe tayari ni juu ya uwezo kamili, huwezi kuongeza kitu kingine chochote.

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Na kisha kama si hivyo, wewe tu na kuongeza kipengele kwa stack.

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Na hatimaye, nyongeza kawaida. Hivyo ni pretty moja kwa moja.

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Hivyo mimi tu kuongeza idadi ya 2.

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Na kama nataka pop, ambayo ina maana kwamba mimi unataka kuondoa

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hiki mwisho kwamba alikuwa aliongeza na kurudi thamani ya hiki,

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Jambo la kwanza mimi na kuangalia ni kwamba stack ni si tupu.

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Kwa sababu kama ni tupu, siwezi kurudi kitu chochote.

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Katika kesi hiyo, mimi nina kurudi -1.

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Vinginevyo, mimi nina kwenda kuongezwa ukubwa wa spec,

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na kurudi namba (s.size).

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Kwa nini mimi kuongezwa ukubwa na kisha kurudi s.size?

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Ni kwa sababu, katika kesi hii, spec ina ukubwa 4,

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na nataka kurudi hiki nne, sawa?

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Lakini ni ripoti ya hiki nne nini? Tatu.

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Tangu mimi ukubwa - ni kwenda kuwa 3, naweza tu kurudi s.numbers (s.size)

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kwa sababu ni 3. Hivyo tu index.

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>> Sasa foleni. Foleni ni pretty much kitu kimoja.

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Tofauti tu ni kwamba badala ya kuwa na mwisho, kwanza nje,

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una kwanza, kwanza nje.

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Pengine kama wewe ni kusubiri kwenda tamasha,

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bila kuwa na furaha kama alikuwa na stack badala ya foleni.

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Kuwa mtu wa mwisho kuja itakuwa mtu wa kwanza kuingia kwenye tamasha hilo.

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Pengine bila kuwa na furaha.

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Katika foleni, mtu wa kwanza kupata katika ni pia mtu wa kwanza kupata nje.

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Hivyo katika ufafanuzi wa foleni, badala ya kuwa na ukubwa katika safu,

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wewe pia kuwa na kichwa, ambayo ni index na mkuu wa stack.

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Hivyo hiki kwanza hivi sasa.

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Enqueue ni kitu kimoja kama kushinikiza kwa mwingi.

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Kama ungekuwa naive sana, ungekuwa tu kusema,

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vizuri, siwezi tu kufanya hasa kitu kimoja kama mimi kwa ajili ya kushinikiza.

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Siwezi kuangalia tu kama si zaidi ya uwezo.

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Kama ni, mimi kurudi uongo, vinginevyo naweza tu nje thamani mpya

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na kisha nyongeza kawaida.

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Lakini kwa nini hii ni sahihi?

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Hebu angalia mfano huu.

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Mimi nina kujaribu enqueue rundo la mambo,

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na kisha mimi nina kwenda dequeue na enqueue.

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Kuna mengi ya amri, lakini ni rahisi sana.

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Mimi nina kwenda enqueue 5, hivyo kuongeza 5, na kisha 7,

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1, 4, 6, na kisha Mimi nataka dequeue kitu,

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ambayo ina maana kwamba mimi nina kwenda kuondoa hiki kwanza.

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Hivyo nina kwenda kuondoa namba 3, sawa?

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hiki kwanza. Sawa.

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Sasa kama mimi kujaribu enqueue kitu kingine, ni nini kinaenda kutokea?

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Kwa mujibu wa utekelezaji yangu,

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Mimi alikuwa anaenda kuweka namba inayofuata katika index q.size.

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Katika kesi hiyo, ukubwa ni 8,

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hivyo index 8 itakuwa haki hapa katika nafasi ya mwisho.

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Kama mimi kujaribu enqueue 1 haki hapa, mimi itakuwa overwriting nafasi ya mwisho

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kwa namba 1, ambayo ni makosa kabisa.

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Nini nataka kufanya ni wrap kuzunguka na kwenda nafasi ya kwanza.

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Labda ungependa kusema tu, vizuri, mimi tu na kuangalia

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kama naweza kweli kuweka kitu pale.

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Kama siyo, mimi tu kusema, oh, mpya uwezo kamili

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ni kweli uwezo wa - 1, na huwezi kuweka hiki huko.

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Lakini ni nini tatizo? Tatizo ni kwamba kama mimi tu dequeue kila kitu sawa hapa

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na kisha mimi kujaribu kuongeza kitu kingine, ingekuwa tu kusema,

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vizuri, walikuwa katika uwezo kamili, ambayo ni 0.

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Hivyo foleni yako ni gone.

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Una kufungia, na njia ya wrapping karibu

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kwamba guys kujifunza katika maono na wengine psets alikuwa akitumia mod.

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Unaweza kujaribu nyumbani kuelewa ni kwa nini ungependa kufanya q.size + q.head

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uwezo mod, lakini kama wewe kuangalia hapa,

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tunaweza kuona kwamba ni kazi.

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Hivyo katika mfano wa mwisho, q.size mara 8

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na kichwa mara 1, kwa sababu ilikuwa nafasi hii hapa wa safu.

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Hivyo itakuwa 8 + 1, 9. Mod uwezo 9 itakuwa 0.

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Itakuwa kwenda index 0. Tutaweza kuwa katika nafasi ya haki.

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Na kisha kujaribu foleni nyumbani.

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Baadhi ya mambo muhimu: kujaribu kuelewa tofauti kati ya stack na foleni.

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Nyumbani, kujaribu kupata familiar sana na utekelezaji wa enqueue, dequeue, kushinikiza na pop.

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Na pia kuelewa wakati ungependa kutumia kila mmoja wao.

184
00:11:16,560 --> 00:11:22,830
>> Basi hebu kupumzika kwa sekunde 10 pamoja na kundi la pokemons.

185
00:11:22,830 --> 00:11:26,080
Na sasa hebu kwenda nyuma na mifumo ya data.

186
00:11:26,080 --> 00:11:29,770
Hash meza. mengi ya watu walikuwa na hofu ya meza hash.

187
00:11:29,770 --> 00:11:33,650
katika kuweka tatizo 6, Spell kusahihisha.

188
00:11:33,650 --> 00:11:35,980
Meza Hash na inajaribu, mengi ya watu kupata hofu yao.

189
00:11:35,980 --> 00:11:38,540
Wanafikiri ni vigumu kuelewa. Yeah?

190
00:11:38,540 --> 00:11:41,490
[Rob Bowden] Tatizo kuweka 5. >> Tatizo kuweka 5, yeah. Shukrani Rob.

191
00:11:41,490 --> 00:11:43,370
Yeah. Sita Huff n 'Puff, yeah.

192
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Tatizo kuweka 5 ilikuwa Spell kusahihisha, na alikuwa na kutumia aidha hash meza au kujaribu.

193
00:11:49,340 --> 00:11:55,360
mengi ya watu walidhani kwamba walikuwa super vigumu kuelewa, lakini wao ni kweli pretty rahisi.

194
00:11:55,360 --> 00:12:01,290
Ni nini meza hash, kimsingi? meza hash ni safu ya orodha wanaohusishwa.

195
00:12:01,290 --> 00:12:06,730
Tofauti pekee kati ya safu na meza hash

196
00:12:06,730 --> 00:12:09,730
ni kwamba katika meza hash una kitu kinachoitwa hash kazi.

197
00:12:09,730 --> 00:12:12,080
Ni heshi nini?

198
00:12:12,080 --> 00:12:13,970
Sijui kama wewe guys unaweza kusoma hapa.

199
00:12:13,970 --> 00:12:16,090
Huu ni mfano wa meza hash.

200
00:12:16,090 --> 00:12:19,220
Hivyo unaweza kuona kwamba una safu na 31 vipengele.

201
00:12:19,220 --> 00:12:22,440
Na nini cha kufanya katika meza hash ni kuwa na heshi

202
00:12:22,440 --> 00:12:26,660
kwamba ni kwenda kutafsiri kwa muhimu, kila int kwa index.

203
00:12:26,660 --> 00:12:31,740
Kama, kwa mfano, kama nataka kuchagua kwa B. Harrison,

204
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Napenda kuweka B. Harrison katika kazi yangu hash,

205
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na heshi atarudi 24.

206
00:12:36,960 --> 00:12:40,930
Hivyo najua kwamba unataka kuhifadhi B. Harrison katika 24.

207
00:12:40,930 --> 00:12:46,580
Hivyo hiyo ni tofauti kati ya kuwa na tu safu na kuwa na meza hash.

208
00:12:46,580 --> 00:12:48,740
Katika meza hash itabidi kazi ambayo ni kwenda kuwaambia

209
00:12:48,740 --> 00:12:54,740
ambapo kuhifadhi data kwamba unataka kuhifadhi.

210
00:12:54,740 --> 00:12:57,040
Kwa hash kazi, unataka kuangalia kwa heshi

211
00:12:57,040 --> 00:13:00,600
kwamba ni deterministic na vizuri kusambazwa.

212
00:13:00,600 --> 00:13:07,810
Kama unaweza kuona hapa, unaweza kuona kwamba mengi ya data kuwa nilitaka kuhifadhi ilikuwa kweli 19

213
00:13:07,810 --> 00:13:12,470
badala ya kutumia 31 na 30 na 29, ambao wote walikuwa huru.

214
00:13:12,470 --> 00:13:16,920
Hivyo heshi kwamba mimi kutumika hakuwa vizuri sana kusambazwa.

215
00:13:16,920 --> 00:13:20,710
Tunaposema vizuri kusambazwa, maana yake ni kwamba tunataka kuwa na,

216
00:13:20,710 --> 00:13:26,520
takribani, angalau 1 au 2 kwa kila moja ya -

217
00:13:26,520 --> 00:13:32,190
kama, tofauti ya 1 au 2 kwa kila moja ya fahirisi katika arrays.

218
00:13:32,190 --> 00:13:43,950
Unataka kuwa, takribani, idadi sawa ya mambo katika orodha ya kila wanaohusishwa katika safu.

219
00:13:43,950 --> 00:13:48,600
Na ni rahisi kuangalia kama ni halali katika meza hash, kuona kama meza hash.

220
00:13:48,600 --> 00:13:51,770
>> Kisha miti. Hii ni mti.

221
00:13:51,770 --> 00:13:56,400
Miti katika sayansi ya kompyuta ni kichwa chini kwa sababu fulani.

222
00:13:56,400 --> 00:14:00,150
Hivyo haki hapa una mizizi ya mti na kisha majani.

223
00:14:00,150 --> 00:14:05,630
Unapaswa tu kujua majina kwa ajili ya wazazi na watoto.

224
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Kila node ana watoto wake, ambayo ni nodes kwamba ni chini ya mzazi.

225
00:14:12,880 --> 00:14:19,660
Hivyo, kwa mfano, 2 ni kwenda kuwa mzazi kwa 3 na kwa mtoto mwingine hapo,

226
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wakati 3 ni kwenda kuwa mzazi kwa 1 na watoto wengine kwamba ni huko.

227
00:14:25,290 --> 00:14:29,990
Na 1 ni kwenda kuwa 3 mtoto, na kadhalika.

228
00:14:29,990 --> 00:14:34,610
Tuna kitu zaidi ya kuvutia, iitwayo binary search mti,

229
00:14:34,610 --> 00:14:39,040
ambayo maadili yote juu ya haki ya node

230
00:14:39,040 --> 00:14:41,660
ni kwenda kuwa juu ya haki, haki hapa - juu ya haki,

231
00:14:41,660 --> 00:14:46,780
ni kwenda kuwa zaidi ya hiki katika mizizi.

232
00:14:46,780 --> 00:14:49,780
Basi, ikiwa mimi na namba 5 hapa, mambo yote juu ya haki

233
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ni kwenda kuwa zaidi ya 5, na upande wa kushoto

234
00:14:51,940 --> 00:14:56,770
mambo yote ni kwenda kuwa chini ya 5.

235
00:14:56,770 --> 00:14:58,780
Kwa nini hii ni muhimu?

236
00:14:58,780 --> 00:15:01,660
Naam, kama nataka kuangalia kama namba 7 ni hapa, kwa mfano,

237
00:15:01,660 --> 00:15:05,960
I just kwenda 5 kwanza na mimi nina kwenda kuona, ni 7 zaidi au chini ya 5?

238
00:15:05,960 --> 00:15:09,540
Ni zaidi, hivyo najua itakuja kuwa juu ya haki ya mti.

239
00:15:09,540 --> 00:15:13,980
Hivyo nina mambo mengi chini kuangalia.

240
00:15:13,980 --> 00:15:19,520
Katika utekelezaji wa binary search mti, node, mimi nina kwenda tu kuwa na data,

241
00:15:19,520 --> 00:15:21,750
hivyo int n, ungeweza pia na kamba

242
00:15:21,750 --> 00:15:23,630
au kitu chochote alitaka.

243
00:15:23,630 --> 00:15:28,100
Wewe tu kuwa makini juu ya kufafanua nini ni zaidi, ni nini chini.

244
00:15:28,100 --> 00:15:30,390
Hivyo kama wewe alikuwa masharti, kwa mfano, unaweza kufafanua

245
00:15:30,390 --> 00:15:34,690
kwamba mambo hayo yote juu ya haki ni kwenda na urefu kubwa,

246
00:15:34,690 --> 00:15:40,940
kushoto ni kwenda na urefu chini, hivyo ni kweli up na wewe.

247
00:15:40,940 --> 00:15:44,930
>> Jinsi naweza kutekeleza kupata kwa BST?

248
00:15:44,930 --> 00:15:47,840
Jambo la kwanza sisi itabidi kufanya ni kuangalia mizizi ya mti ikiwa ni null.

249
00:15:47,840 --> 00:15:50,920
Kama ni NULL, ina maana kwamba kitu si kuna

250
00:15:50,920 --> 00:15:53,330
kwa sababu huna hata na mti, sawa?

251
00:15:53,330 --> 00:15:55,790
Basi, mimi kurudi uongo.

252
00:15:55,790 --> 00:15:58,740
Vinginevyo, mimi nina kwenda kuangalia kama idadi ni kubwa

253
00:15:58,740 --> 00:16:01,720
kuliko thamani katika mizizi.

254
00:16:01,720 --> 00:16:04,250
Mimi nina kwenda kujaribu kupata hiki juu ya haki

255
00:16:04,250 --> 00:16:08,590
ya mti.

256
00:16:08,590 --> 00:16:11,310
Unaweza kuona kwamba mimi nina kutumia kujirudia hapa.

257
00:16:11,310 --> 00:16:14,150
Na kisha kama ni kidogo, mimi nina kwenda kuangalia upande wa kushoto.

258
00:16:14,150 --> 00:16:18,330
Na hatimaye, vinginevyo, kama si chini au si zaidi,

259
00:16:18,330 --> 00:16:20,660
maana yake ni kwamba ni thamani yenyewe.

260
00:16:20,660 --> 00:16:23,010
Hivyo mimi tu kurudi kweli.

261
00:16:23,010 --> 00:16:26,360
Unaweza kuona hapa kwamba mimi kutumika kama, kama, kama.

262
00:16:26,360 --> 00:16:30,820
Na kumbuka, katika jaribio 0, tulikuwa na tatizo kwamba alikuwa kama, kama, kama,

263
00:16:30,820 --> 00:16:32,780
na walipaswa kupata uzembe,

264
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na uzembe ni kwamba unaweza kutumika kama.

265
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Unapaswa kuwa kutumika kama, mwingine kama, mwingine kama, na mwingine.

266
00:16:39,060 --> 00:16:44,240
Kwa hiyo, mimi kutumia mwingine kama na mwingine kama na mwingine hapa?

267
00:16:44,240 --> 00:16:46,200
Je, mtu yeyote - yeah?

268
00:16:46,200 --> 00:16:51,140
[Mwanafunzi akizungumza, inaudible]

269
00:16:51,140 --> 00:16:53,480
Hiyo ni kamilifu. Hivyo yeye kusema kwamba haijalishi,

270
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kwa sababu tu ya uzembe kwamba tulikuwa kabla ya

271
00:16:55,930 --> 00:16:59,550
ni kwamba kwa sababu, labda kama baadhi ya hali ilikuwa kuridhika,

272
00:16:59,550 --> 00:17:03,570
hivyo kuwa utekelezaji wake, lakini basi walikuwa wanakwenda kuangalia yote ya hali nyingine.

273
00:17:03,570 --> 00:17:06,319
Lakini katika kesi hii, ni kurudi mara moja, hivyo hana jambo.

274
00:17:06,319 --> 00:17:09,220
Hivyo huna kutumia mwingine kama.

275
00:17:09,220 --> 00:17:11,740
>> Na hatimaye, hebu majadiliano juu ya anajaribu,

276
00:17:11,740 --> 00:17:13,800
ambayo ni favorite ya kila mtu.

277
00:17:13,800 --> 00:17:15,980
kujaribu ni mti wa arrays.

278
00:17:15,980 --> 00:17:20,369
Ni kwa haraka sana kwa kuangalia juu maadili, lakini inatumia mengi ya kumbukumbu.

279
00:17:20,369 --> 00:17:22,530
Na ni kawaida kuchuja maneno, hivyo wakati

280
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unataka kutekeleza, kwa mfano, mimi sijui, kama kitabu cha simu katika simu yako

281
00:17:27,920 --> 00:17:30,440
na unataka kuwa na uwezo wa aina B

282
00:17:30,440 --> 00:17:32,510
na tu na majina ya watu ambao wana B.

283
00:17:32,510 --> 00:17:37,960
Ni rahisi sana kutekeleza kwamba kwa kutumia kujaribu, kwa mfano.

284
00:17:37,960 --> 00:17:39,820
Jinsi gani unaweza kufafanua node katika kujaribu?

285
00:17:39,820 --> 00:17:43,910
Wewe tu kuwa na bool kwamba ni kwenda kuwa is_word.

286
00:17:43,910 --> 00:17:48,660
Kwamba inawakilisha kwamba kwa kutumia wahusika wote kabla ya node,

287
00:17:48,660 --> 00:17:51,920
walikuwa na uwezo wa kuunda neno,

288
00:17:51,920 --> 00:17:57,230
na kisha itabidi safu ya kuyatumia kwa nodes.

289
00:17:57,230 --> 00:18:03,120
Unaweza kuona kwamba tuna safu ya nodes mzazi, hivyo nodi * safu? Yeah?

290
00:18:03,120 --> 00:18:06,050
Basi hebu angalia jinsi kazi. Kwa kuangalia Spell,

291
00:18:06,050 --> 00:18:08,230
tuna safu ya 27 vipengele,

292
00:18:08,230 --> 00:18:12,150
kwa sababu tuna kila barua pamoja na apostrophe.

293
00:18:12,150 --> 00:18:17,800
Kabla ya hapa Mimi tu kwenda kutumia 2 kwa sababu nataka kuwa na uwezo wa kuandika kwenye ubao.

294
00:18:17,800 --> 00:18:20,230
Sawa. Hivyo hii ni mfano wa kujaribu.

295
00:18:20,230 --> 00:18:25,600
Kama mimi tu kufafanua node kwanza, mimi itabidi safu ya 2 mambo

296
00:18:25,600 --> 00:18:29,290
kwamba ni 2 kuyatumia kwa NULL, hivyo mimi tu ya kuweka 'a' na 'b'.

297
00:18:29,290 --> 00:18:32,430
Na mimi nina kwenda na bool kwamba anasema is_word.

298
00:18:32,430 --> 00:18:34,420
Ni kwenda kuwa uongo kwa moja kwanza,

299
00:18:34,420 --> 00:18:37,370
tu kwa sababu, kabla ya kuwa huna wahusika yoyote.

300
00:18:37,370 --> 00:18:40,900
Hivyo neno tupu ni neno. Hivyo ni ya uongo.

301
00:18:40,900 --> 00:18:46,320
Kama mimi nataka kuongeza 'a' kwa kamusi hii, gani mimi na kwa nini?

302
00:18:46,320 --> 00:18:49,760
Napenda tu na malloc node mpya kwa ajili ya 'a',

303
00:18:49,760 --> 00:18:54,630
na kisha kuongeza maneno yake kwa kweli.

304
00:18:54,630 --> 00:19:00,180
Hivyo tu inawakilisha kuwa baada ya 'ni kwenda kuwa kweli. Mantiki?

305
00:19:00,180 --> 00:19:04,120
Basi, nataka kuongeza 'ba', mimi itabidi malloc 1 kwa 'b',

306
00:19:04,120 --> 00:19:07,550
na basi mimi nina kwenda kuanzisha boolean kwa uongo,

307
00:19:07,550 --> 00:19:10,160
kwa sababu 'b' na yenyewe ni neno.

308
00:19:10,160 --> 00:19:13,010
Kisha mimi nina kwenda malloc mtu mwingine kwa 'a', hivyo 'ba',

309
00:19:13,010 --> 00:19:16,290
na basi mimi nina kwenda kuanzisha ni neno kwa kweli.

310
00:19:16,290 --> 00:19:18,950
Kwa sababu 'ba' ni neno la Mungu.

311
00:19:18,950 --> 00:19:21,910
Na kisha kama nataka kuona kama 'b' ni katika kamusi hii,

312
00:19:21,910 --> 00:19:26,730
Mimi unaweza tu kwenda kwa moja ya kwanza, 'b'. Mimi kwenda chini, na mimi kuangalia ni neno, na anasema uongo.

313
00:19:26,730 --> 00:19:30,110
Hivyo si neno. Kama mimi nataka kuangalia 'ba',

314
00:19:30,110 --> 00:19:38,010
Mimi kwenda moja ya kwanza, 'b', na kisha kwenda 'a', na mimi kuona kweli, hivyo ni neno. Mantiki?

315
00:19:38,010 --> 00:19:41,950
mengi ya watu kupata kuchanganyikiwa na inajaribu. No?

316
00:19:41,950 --> 00:19:44,740
>> Hatimaye, Huffman coding. Huffman coding ni muhimu sana

317
00:19:44,740 --> 00:19:47,550
kuokoa kumbukumbu na kubana Nakala files,

318
00:19:47,550 --> 00:19:52,270
kwa sababu tu mara nyingi matumizi ya 'a' na 'e', ​​kwa mfano,

319
00:19:52,270 --> 00:19:57,710
katika hati yako, lakini sijui kama wewe guys kutumia 'q' au 'z' kama sana.

320
00:19:57,710 --> 00:20:02,040
Kuwa tu 1 Byte kwa kila tabia moja,

321
00:20:02,040 --> 00:20:08,520
kila moja - wahusika 256 kwamba tuna katika meza ASCII si mojawapo sana,

322
00:20:08,520 --> 00:20:11,410
kwa sababu tu kuna baadhi ya wahusika kwamba matumizi ya zaidi,

323
00:20:11,410 --> 00:20:15,180
hivyo unapaswa pengine kutumia chini ya kumbukumbu kwa hizo.

324
00:20:15,180 --> 00:20:17,560
Je, mimi kutumia Huffman coding?

325
00:20:17,560 --> 00:20:20,010
Sisi kufanya mti Huffman.

326
00:20:20,010 --> 00:20:23,370
 Mti Huffman ina nodes

327
00:20:23,370 --> 00:20:27,760
kuwa na ishara kwamba ni kwenda kuwa kama, 'a', 'b', 'c', barua,

328
00:20:27,760 --> 00:20:32,990
chochote barua una, frequency kwamba ni ya mzunguko neno hilo limetumika katika maandiko,

329
00:20:32,990 --> 00:20:36,280
kwamba walikuwa kujenga mti Huffman kwa,

330
00:20:36,280 --> 00:20:41,800
na kisha nodi kwamba inaenda upande wa kushoto wa mti Huffman

331
00:20:41,800 --> 00:20:47,210
na node nyingine ambayo inaenda kwa haki. Hivyo tu kama mti.

332
00:20:47,210 --> 00:20:49,440
Jinsi gani unaweza kujenga mti Huffman?

333
00:20:49,440 --> 00:20:54,020
Wewe ni kwenda kuchukua 2 nodes kuwa na mikondo ya chini.

334
00:20:54,020 --> 00:20:56,490
Kama una tie wewe ni kwenda kuchukua 2 nodes

335
00:20:56,490 --> 00:20:59,870
kuwa na maadili ya chini ASCII pia.

336
00:20:59,870 --> 00:21:02,420
Basi wewe ni kwenda kujenga mti mpya nje ya wale 2 nodes

337
00:21:02,420 --> 00:21:08,030
kwamba ni kwenda na frequency pamoja katika mzazi nodi.

338
00:21:08,030 --> 00:21:13,240
Na kisha utaenda kuondoa 2 watoto kutoka msitu

339
00:21:13,240 --> 00:21:15,570
na kuchukua nafasi yao na mzazi.

340
00:21:15,570 --> 00:21:18,930
Na wewe kwenda kurudia kwamba mpaka wewe tu 1 mti katika msitu.

341
00:21:18,930 --> 00:21:23,840
Basi hebu angalia jinsi gani kufanya mti Huffman kwa ZAMYLA.

342
00:21:23,840 --> 00:21:29,220
Unaweza kuona hapa kwamba barua zote na frequency 1 ila kwa 'A'; ambayo ina mzunguko 2.

343
00:21:29,220 --> 00:21:34,090
Basi, mimi kuundwa nodes kwa barua zote mimi kuweka katika utaratibu wa thamani ASCII na mzunguko.

344
00:21:34,090 --> 00:21:40,090
Basi, ikiwa mimi unataka kujenga mti kwanza, itakuwa na 'L' na 'M'.

345
00:21:40,090 --> 00:21:43,100
Hivyo ni hapa. mzunguko wa jozi itakuwa 2

346
00:21:43,100 --> 00:21:49,470
kwa sababu ni 1 + 1, kisha 2 pili na mikondo ya chini ni 'Y' na 'Z'.

347
00:21:49,470 --> 00:21:53,180
Na kisha mimi na wote kuwa - na mzunguko wa 2.

348
00:21:53,180 --> 00:22:00,470
Hivyo ambayo ndio ni wale ambao chini thamani ASCII kwa moja ijayo?

349
00:22:00,470 --> 00:22:04,830
'A' na 'L'. Basi, mimi kujenga node mpya,

350
00:22:04,830 --> 00:22:09,930
na hatimaye, ni 4 na 2, hivyo 2 ni kwenda kuwa upande wa kushoto.

351
00:22:09,930 --> 00:22:12,430
Na hii ni mti Huffman.

352
00:22:12,430 --> 00:22:16,060
Basi, nataka kuandika baadhi ya maandishi,

353
00:22:16,060 --> 00:22:24,440
kama katika binary kubadili kwa maandishi, kwa kutumia mti Huffman ni rahisi sana.

354
00:22:24,440 --> 00:22:30,220
Kwa mfano, kama mimi kusema kwamba kuhamia upande wa kushoto ni 0 na kuhamia haki ni 1,

355
00:22:30,220 --> 00:22:32,410
Ni yale ambayo kwenda kuwakilisha?

356
00:22:32,410 --> 00:22:35,530
Hivyo kama 1, 1, hivyo haki, haki,

357
00:22:35,530 --> 00:22:40,370
na kisha 0, hivyo kushoto itakuwa L, na kisha 1, 0, 0.

358
00:22:40,370 --> 00:22:43,950
Hivyo 1, 0, hivyo 1 tu, 0, 'A'.

359
00:22:43,950 --> 00:22:47,540
Na kisha 0, 1, hivyo 'Z'.

360
00:22:47,540 --> 00:22:52,170
Na kisha 1, 0, 0 - no.

361
00:22:52,170 --> 00:22:56,780
0, 0 itakuwa 'Y', hivyo Lazy.

362
00:22:56,780 --> 00:23:06,060
Ili wote kwa ajili yangu, Rob ya kwenda kuchukua juu.

363
00:23:06,060 --> 00:23:08,400
>> [Rob Bowden] Hivyo, wiki 7 mambo ya ajabu.

364
00:23:08,400 --> 00:23:11,390
Sisi tumepewa mengi kwenda juu kweli haraka.

365
00:23:11,390 --> 00:23:13,430
Bitwise operators, buffer kufurika,

366
00:23:13,430 --> 00:23:16,760
CS50 maktaba, kisha HTML, HTTP, CSS.

367
00:23:16,760 --> 00:23:20,990
Wote katika kama dakika 15 hadi 20.

368
00:23:20,990 --> 00:23:24,330
Bitwise operators. Kuna 6 yao kwamba unahitaji kujua.

369
00:23:24,330 --> 00:23:31,200
Bitwise na bitwise au, XOR, kushoto kuhama, mabadiliko ya haki, na si.

370
00:23:31,200 --> 00:23:35,420
Haki kuhama na si wewe vigumu kuona katika hotuba wakati wote.

371
00:23:35,420 --> 00:23:40,480
Tutaweza kwenda juu haraka hapa, lakini ni vizuri kujua kwamba hizi ni 6 kwamba zipo.

372
00:23:40,480 --> 00:23:45,070
Kumbuka kwamba bitwise operators ni kama wakati wa kufanya 3 + 4.

373
00:23:45,070 --> 00:23:49,420
Wewe ni si kushughulika na binary ya 3 na 4.

374
00:23:49,420 --> 00:23:56,550
Pamoja na bitwise operators wewe ni kweli kushughulika na bits ya mtu binafsi ya idadi 3 na 4.

375
00:23:56,550 --> 00:23:59,120
>> Hivyo moja ya kwanza tutaweza kusema ni bitwise si,

376
00:23:59,120 --> 00:24:02,340
na yote ni gani ni flip bits wote.

377
00:24:02,340 --> 00:24:05,500
Hivyo hapa, kama wewe ni kuandika hii katika C, bila kuandika

378
00:24:05,500 --> 00:24:09,380
kama ~ 11,011 au chochote, ungekuwa kuandika kama ~ 4,

379
00:24:09,380 --> 00:24:12,970
na kisha itakuwa flip uwakilishi binary ya 4.

380
00:24:12,970 --> 00:24:24,800
Hivyo hapa, ~ ya baadhi ya idadi binary 1101101 ni kwenda hasa flip 1 wote wa 0 na 0 wote wa 1 ya.

381
00:24:24,800 --> 00:24:27,600
Kama mimi kusema, ni matumizi ya mara kwa mara hii,

382
00:24:27,600 --> 00:24:30,830
na sisi utaona katika kidogo, ni kama tunataka kuja na baadhi ya idadi

383
00:24:30,830 --> 00:24:35,460
ambapo wote wa bits ni 1, ila kwa mmoja wao.

384
00:24:35,460 --> 00:24:38,560
Hivyo ni kawaida rahisi kueleza idadi

385
00:24:38,560 --> 00:24:40,630
ambapo tu kwamba kidogo moja ni kuweka,

386
00:24:40,630 --> 00:24:44,650
na kisha kuchukua ~ yake, hivyo kila kidogo nyingine ni kuweka ila kwa kuwa moja.

387
00:24:44,650 --> 00:24:50,300
Hivyo kwamba ni nini sisi ni kwenda kutumia zaidi katika kidogo.

388
00:24:50,300 --> 00:24:58,220
>> Bitwise au. Hapa ni 2 idadi binary, na hizi namba 2

389
00:24:58,220 --> 00:25:00,780
ni pretty mwakilishi, kwa vile wao kuwakilisha kila iwezekanavyo

390
00:25:00,780 --> 00:25:07,290
mchanganyiko wa bits unaweza haja ya kufanya kazi juu.

391
00:25:07,290 --> 00:25:13,540
Hapa, wakati mimi or'd kila kidogo, sisi ni kwenda tu kulinganisha moja kwa moja chini.

392
00:25:13,540 --> 00:25:15,410
Hivyo upande wa kushoto tuna 1 na 1.

393
00:25:15,410 --> 00:25:20,510
Wakati mimi bitwise | hizo, je, Mimi naenda kupata? Moja.

394
00:25:20,510 --> 00:25:25,320
Kisha bitwise | 0 na 1 ni kwenda nipe? Moja.

395
00:25:25,320 --> 00:25:27,840
Bitwise 1 na 0 kinaenda kuwa kitu kimoja, moja.

396
00:25:27,840 --> 00:25:31,880
Bitwise 0 | 0 ni anaenda kunipa 0.

397
00:25:31,880 --> 00:25:37,300
Hivyo kesi tu ambapo mimi kupata 0 ni katika 0 | 0 kesi.

398
00:25:37,300 --> 00:25:40,020
Na unaweza kufikiria kwamba kama ORS yako mantiki.

399
00:25:40,020 --> 00:25:44,830
Hivyo kama wewe kufikiria 1 kama kweli na 0 kama uongo, kitu hiyo inatumika hapa.

400
00:25:44,830 --> 00:25:50,040
Hivyo kweli au kweli ni kweli; kweli au uongo ni kweli.

401
00:25:50,040 --> 00:25:57,150
Uongo au kweli ni kweli; uongo au uongo ni kitu tu kwamba ni kweli uongo.

402
00:25:57,150 --> 00:26:00,100
Hapa ni mfano kwamba unapaswa kujua

403
00:26:00,100 --> 00:26:05,160
kama mfano nzuri ya na watoa huduma bitwise ni kutumika.

404
00:26:05,160 --> 00:26:08,660
Hapa kama sisi au mtaji 'A' na Ox20,

405
00:26:08,660 --> 00:26:11,830
na tutaangalia hizi katika pili, sisi kupata kitu fulani.

406
00:26:11,830 --> 00:26:16,020
Na kama sisi au lowercase 'kwa Ox20, sisi kupata kitu fulani.

407
00:26:16,020 --> 00:26:26,750
Basi hebu vuta juu ya meza ASCII.

408
00:26:26,750 --> 00:26:34,000
Sawa. Hapa tunaona kuwa 'A' ni -

409
00:26:34,000 --> 00:26:36,920
hapa tuna 'A' ni decimal 65.

410
00:26:36,920 --> 00:26:45,120
Lakini nitakwenda kwa hexadesimoli, ambayo ni Ox41.

411
00:26:45,120 --> 00:26:48,280
Pretty uhakika tuliona katika darasa. Nadhani tuliona katika darasa

412
00:26:48,280 --> 00:26:52,730
kwamba ni pretty rahisi kubadili kutoka hexadesimoli kwa binary.

413
00:26:52,730 --> 00:26:55,280
Hivyo hapa, kama nataka kuweka 4 katika binary,

414
00:26:55,280 --> 00:26:59,550
kwamba tu kwenda kuwa 0100.

415
00:26:59,550 --> 00:27:03,620
Hii ni 1 ya mahali, 2 kuchukua nafasi ya 4 ya mahali, hivyo hii ni 4.

416
00:27:03,620 --> 00:27:08,550
Basi naweza mgawanyiko 1 katika binary, ambayo ni kwenda kuwa 0001.

417
00:27:08,550 --> 00:27:14,280
Na hivyo hii ni kwenda kuwa uwakilishi wa 'A' katika binary.

418
00:27:14,280 --> 00:27:22,720
Kuchukua lowercase ', ni sasa kwenda kuwa Ox61,

419
00:27:22,720 --> 00:27:27,050
ambapo, kugawanyika haya juu katika binary yake, hivyo 6 -

420
00:27:27,050 --> 00:27:37,830
Hebu kweli kufanya hivyo - ni hakuna kifutio? Raba.

421
00:27:37,830 --> 00:27:48,220
Ox61. Hivyo kugawanyika 6 katika binary ni kwenda kuwa 0 + 4 + 2 + 0.

422
00:27:48,220 --> 00:27:54,610
Na splitting 1 ni kwenda kuwa 0001.

423
00:27:54,610 --> 00:27:56,520
Kuangalia tofauti kati ya hizi 2,

424
00:27:56,520 --> 00:28:04,250
tunaona kwamba tofauti tu kati ya lowercase na mji mkuu wa 'A' ni hii moja kidogo.

425
00:28:04,250 --> 00:28:11,810
Hivyo kuja nyuma hapa - sawa.

426
00:28:11,810 --> 00:28:15,920
Kuja nyuma hapa, kama sisi kuangalia nini kidogo Ox20 ni,

427
00:28:15,920 --> 00:28:22,210
hivyo kugawanyika Ox20 katika binary yake,

428
00:28:22,210 --> 00:28:27,310
ni 0010, 0000.

429
00:28:27,310 --> 00:28:33,470
Ox20, kidogo tu kwamba ni kuweka ni kidogo hii kwamba sisi ni wasiwasi na,

430
00:28:33,470 --> 00:28:38,210
kwa byte kati ya mji mkuu na ndogo '.

431
00:28:38,210 --> 00:28:47,610
Kama mimi au 'A', ambayo ni hii moja, 'A',

432
00:28:47,610 --> 00:28:50,580
iwapo mimi au 'A' na Ox20,

433
00:28:50,580 --> 00:28:53,490
je, Mimi naenda kupata?

434
00:28:53,490 --> 00:28:58,960
[Mwanafunzi, inaudible] >> Herufi za chini 'a', kwa sababu ni kwenda flip kidogo hii 1.

435
00:28:58,960 --> 00:29:04,170
Na iwapo mimi au 'kwa Ox20, je, Mimi naenda kupata?

436
00:29:04,170 --> 00:29:08,780
Herufi za chini, kwa sababu tu oring 'kwa Ox20,

437
00:29:08,780 --> 00:29:14,580
Mimi tu kwenda oring hii kidogo moja kwa 1; ni tayari 1, hivyo haijalishi.

438
00:29:14,580 --> 00:29:17,960
Ili tuweze kupata 'a' na 'a'.

439
00:29:17,960 --> 00:29:24,820
>> Bitwise na. Tena, tunaweza kufikiria hii kama yetu mwenzake mantiki na.

440
00:29:24,820 --> 00:29:28,180
Upande wa kushoto tuna kweli & kweli.

441
00:29:28,180 --> 00:29:31,160
Ni kwenda kuwa ni kweli, na kwa wote wa kesi,

442
00:29:31,160 --> 00:29:36,270
uongo & kweli au ya kweli na uongo, au uongo & uongo,

443
00:29:36,270 --> 00:29:38,550
hakuna mambo hayo ni kweli.

444
00:29:38,550 --> 00:29:44,170
Hivyo kile sisi kuishia kupata ni 1000.

445
00:29:44,170 --> 00:29:48,830
Basi sasa, hapa, hapa ambapo nimekuwa kutumika bitwise muaminifu si,

446
00:29:48,830 --> 00:29:52,230
ambapo tulikuwa na Ox20.

447
00:29:52,230 --> 00:29:54,350
Hivyo hii ni Ox20.

448
00:29:54,350 --> 00:29:59,570
Sasa nini nataka kufanya, bitwise ~ ya Ox20.

449
00:29:59,570 --> 00:30:03,600
Hiyo ni kwenda flip bits wote.

450
00:30:03,600 --> 00:30:09,330
Hivyo nina 1101, 1111.

451
00:30:09,330 --> 00:30:18,940
Na hivyo 'anded na ~ Ox20 ni kwenda nipe nini?

452
00:30:18,940 --> 00:30:22,430
tu kidogo sisi kwa kweli wanahitaji kufikiria ni hii moja,

453
00:30:22,430 --> 00:30:26,020
tangu, kama wote wa bits hizi ni kuweka 1,

454
00:30:26,020 --> 00:30:29,000
kisha tunakwenda kupata nini hasa 'A' ilikuwa,

455
00:30:29,000 --> 00:30:31,260
ila kwa, pengine, nini kidogo hii ni.

456
00:30:31,260 --> 00:30:34,460
Kwa sababu kama ilikuwa ni 1, sasa ni kwenda kuweka 0,

457
00:30:34,460 --> 00:30:39,810
kwa sababu chochote hii ni anded na hii ni kwenda 0.

458
00:30:39,810 --> 00:30:43,280
Kwa hiyo kile ni 'A' & ~ Ox20 kwenda nipe?

459
00:30:43,280 --> 00:30:48,200
[Wanafunzi kujibu, inaudible] >> Na nini ni 'a' na - ni 'A'.

460
00:30:48,200 --> 00:30:52,170
Na kile ambacho ni '& ~ Ox20 kwenda nipe?

461
00:30:52,170 --> 00:30:56,720
'A.' Kwa sababu hii kwa sasa ni 1.

462
00:30:56,720 --> 00:30:59,570
Anding na hii 0 ni kwenda kufanya ni 0,

463
00:30:59,570 --> 00:31:02,530
na sasa sisi ni kwenda kupata 'A'.

464
00:31:02,530 --> 00:31:06,600
>> Wote ni 'A,' na mwisho lakini si uchache wa aina hii,

465
00:31:06,600 --> 00:31:10,830
tuna XOR. Ni sana kama au,

466
00:31:10,830 --> 00:31:14,400
ila ina maana peke au.

467
00:31:14,400 --> 00:31:18,420
Hii ni kama nini kawaida kufikiria kama au katika ulimwengu wa kweli.

468
00:31:18,420 --> 00:31:23,190
Hivyo kufanya ama 'x' au 'y', lakini si wote.

469
00:31:23,190 --> 00:31:28,700
Hapa 1 ^ 1 ni kwenda 0.

470
00:31:28,700 --> 00:31:33,650
Kwa sababu kweli, hii ni - haifanyi kazi kama pamoja na mantiki kweli na wa uongo

471
00:31:33,650 --> 00:31:37,150
kama bitwise & na au kufanya,

472
00:31:37,150 --> 00:31:40,100
lakini ni kweli ^ kweli ni ya uongo.

473
00:31:40,100 --> 00:31:44,810
Kwa sababu sisi tu wanataka kurudi kweli kama tu mmoja wao ni kweli.

474
00:31:44,810 --> 00:31:50,950
Hivyo 1 ^ 1 ni 0. Nini kuhusu 0 ^ 1?

475
00:31:50,950 --> 00:31:56,010
Ni 1. 1 ^ 0 ni 1, 0 ^ 0 ni 0.

476
00:31:56,010 --> 00:32:03,890
Hivyo chini ya hali zote, 0 bitwise kitu 0 ni kwenda 0.

477
00:32:03,890 --> 00:32:10,270
1 bitwise kitu 0 au 0 bitwise 1,

478
00:32:10,270 --> 00:32:14,660
kama ni | ama ^, utakuwa ni 1, na kama ni & utakuwa 0.

479
00:32:14,660 --> 00:32:20,850
Na kesi tu ambapo 1 bitwise 1 ni si 1 ni pamoja na ya kipekee au.

480
00:32:20,850 --> 00:32:24,580
Hiyo ni 0110.

481
00:32:24,580 --> 00:32:36,520
Hivyo hapa sasa, kwa kutumia XOR - hivyo tuko nyuma katika 20.

482
00:32:36,520 --> 00:32:43,480
'^ Ox20 ni hizi 2 bits sisi ni kulinganisha.

483
00:32:43,480 --> 00:32:50,020
Hivyo 1 ^ 0 ni kwenda nipe nini? moja.

484
00:32:50,020 --> 00:32:58,430
'^ Ox20 ni kwenda nipe? Herufi za chini.

485
00:32:58,430 --> 00:33:04,010
'^ Ox20 ni kwenda nipe? Capital A.

486
00:33:04,010 --> 00:33:09,310
Kwa sababu chochote hii ni kufanya, XORing huu kwa Ox20

487
00:33:09,310 --> 00:33:15,380
ni ufanisi flipping chochote kidogo hii ni.

488
00:33:15,380 --> 00:33:21,240
Kama hii ni 0, ni sasa kwenda kuwa 1.

489
00:33:21,240 --> 00:33:26,160
Tangu hii ni 1, 1 ^ 1 ni 0.

490
00:33:26,160 --> 00:33:33,280
Hivyo yetu 'imekuwa' A ', na' A 'yetu imekuwa'.

491
00:33:33,280 --> 00:33:36,910
Hivyo XOR ni njia ya kweli rahisi ya tu flipping kesi.

492
00:33:36,910 --> 00:33:39,960
Unataka tu iterate juu ya kamba ya barua

493
00:33:39,960 --> 00:33:44,330
na mbadala kesi ya kila tabia moja,

494
00:33:44,330 --> 00:33:50,680
wewe tu XOR kila kitu kwa Ox20.

495
00:33:50,680 --> 00:33:55,220
>> Sasa tuna kushoto kuhama. Kushoto mabadiliko ni kwenda tu, kimsingi,

496
00:33:55,220 --> 00:34:01,250
kushinikiza wote wa idadi ya ndani, au wa kushoto, na kuingiza 0 ya nyuma yao.

497
00:34:01,250 --> 00:34:05,550
Kwa hiyo hapa tuna 00,001,101.

498
00:34:05,550 --> 00:34:08,560
Tunakwenda kushinikiza 3 0 katika kutoka kulia,

499
00:34:08,560 --> 00:34:13,580
na sisi kupata 01,101,000.

500
00:34:13,580 --> 00:34:16,380
Katika suala nonbinary,

501
00:34:16,380 --> 00:34:24,699
tunaona kwamba kwamba ni kweli kushughulika 13 wa kushoto-kubadilishwa na 3, ambayo inatupa 104.

502
00:34:24,699 --> 00:34:32,530
Hivyo kushoto shifting, tunaona hapa, x << y kimsingi ni x * 2 ^ y.

503
00:34:32,530 --> 00:34:40,139
13 * 2 ^ 3, 2 ^ 3 ni 8, hivyo 13 * 8 ni 104.

504
00:34:40,139 --> 00:34:45,679
Kama wewe tu kufikiri juu ya binary kwa ujumla, jinsi kila tarakimu,

505
00:34:45,679 --> 00:34:49,530
kama sisi kuanza kutoka kulia, ni 1 ya mahali, kisha 2 ya mahali, kisha 4 ya mahali.

506
00:34:49,530 --> 00:34:51,330
Hivyo kwa kusukuma katika 0 kutoka haki,

507
00:34:51,330 --> 00:34:55,080
tuko tu kusukuma mambo ambayo yalikuwa katika 4 kuchukua nafasi ya 8 ya mahali,

508
00:34:55,080 --> 00:34:57,920
na mambo ambayo yalikuwa katika 8 ya mahali 16 kuchukua nafasi ya.

509
00:34:57,920 --> 00:35:01,280
Kuhama kila tu kuzidisha kwa 2. Yeah?

510
00:35:01,280 --> 00:35:05,210
[Mwanafunzi] Nini kinachotokea kama wewe kubadilishwa kwa 5?

511
00:35:05,210 --> 00:35:10,790
[Bowden] Kama kubadilishwa kwa 5 ungependa tu kupoteza tarakimu.

512
00:35:10,790 --> 00:35:15,410
Bila ya shaka, ni kitu kimoja. Kama, integers ni bits 32 tu,

513
00:35:15,410 --> 00:35:20,750
hivyo kama wewe kuongeza 2 kwa kweli kubwa integers, ni tu haiendani na katika integer.

514
00:35:20,750 --> 00:35:23,660
Hivyo kitu kimoja hapa ni. Kama kubadilishwa kwa 5,

515
00:35:23,660 --> 00:35:25,650
sisi ingekuwa tu kupoteza moja.

516
00:35:25,650 --> 00:35:28,820
Na kwamba ni aina ya kile maana ya "takribani,"

517
00:35:28,820 --> 00:35:37,470
ambapo kama wewe kuhama mbali pia, wewe kupoteza bits.

518
00:35:37,470 --> 00:35:39,830
>> Haki mabadiliko ni kwenda kuwa kinyume,

519
00:35:39,830 --> 00:35:43,090
ambapo tunakwenda mkupuo 0 ya mbali mwisho,

520
00:35:43,090 --> 00:35:48,400
na kwa madhumuni yetu, kujaza 0 kutoka upande wa kushoto.

521
00:35:48,400 --> 00:35:52,910
Hivyo kufanya hivyo, sisi ni kimsingi kupunguza nini tulikuwa tayari amefanya.

522
00:35:52,910 --> 00:35:57,780
Na sisi kuona kwamba tatu 0 juu ya haki tu kuanguka mbali,

523
00:35:57,780 --> 00:36:02,020
na tuna kusukuma 1101 njia yote ya haki.

524
00:36:02,020 --> 00:36:08,380
Hii ni kufanya 104 >> 3, ambayo ni, kwa ufanisi, x / 2 ^ y.

525
00:36:08,380 --> 00:36:11,200
Basi sasa, hapa, ni wazo sawa.

526
00:36:11,200 --> 00:36:18,720
Kwa nini ni tu takribani x / 2 ^ y, na si kweli x / 2 ^ y?

527
00:36:18,720 --> 00:36:22,240
Kwa sababu kama alikuwa kubadilishwa kwa 4, napenda wamepoteza 1.

528
00:36:22,240 --> 00:36:25,950
Kimsingi, nini unafikiri, tu kufikiria integer mgawanyiko kwa ujumla.

529
00:36:25,950 --> 00:36:31,070
Hivyo, kama 5/2 ni 2. Siyo 2.5.

530
00:36:31,070 --> 00:36:35,000
Ni wazo sawa hapa. Wakati sisi kugawanya na 2,

531
00:36:35,000 --> 00:36:39,910
tunaweza kupoteza bits isiyo ya kawaida njiani.

532
00:36:39,910 --> 00:36:43,870
Hivyo sasa - hiyo ni kwa bitwise. Hayo ni yote unahitaji kujua.

533
00:36:43,870 --> 00:36:46,340
Kumbuka kesi ya matumizi tuliona katika darasa,

534
00:36:46,340 --> 00:36:49,340
kama mask kidogo ni muhimu kwa ajili ya bitwise operators,

535
00:36:49,340 --> 00:36:53,220
au matumizi yao kwa kidogo masks.

536
00:36:53,220 --> 00:36:58,620
Barua herufi kubwa na ndogo, kubadili ni mfano pretty prototypical.

537
00:36:58,620 --> 00:37:01,640
>> Sawa, hivyo buffer mashambulizi kufurika.

538
00:37:01,640 --> 00:37:05,110
Mtu yeyote kukumbuka nini ilikuwa na makosa na kazi hii?

539
00:37:05,110 --> 00:37:10,140
Taarifa sisi alitangaza safu ya ka 12, chars 12,

540
00:37:10,140 --> 00:37:18,510
na kisha sisi nakala katika buffer yetu ya 12 chars string nzima bar.

541
00:37:18,510 --> 00:37:25,080
Hivyo tatizo ni nini hapa?

542
00:37:25,080 --> 00:37:32,270
idadi uchawi 12 lazima pretty much mara moja pop nje kama - kwa nini 12?

543
00:37:32,270 --> 00:37:35,050
Nini kama bar hutokea kwa kuwa wahusika zaidi ya 12?

544
00:37:35,050 --> 00:37:41,200
Nini kama bar ni mamilioni ya wahusika?

545
00:37:41,200 --> 00:37:46,010
Hapa suala ni memcpy. Kama bar ni muda wa kutosha,

546
00:37:46,010 --> 00:37:50,330
itakuwa tu kabisa - 'c', 'c' haina huduma kuwa ni wahusika 12 tu;

547
00:37:50,330 --> 00:37:53,280
'C' haina huduma ya kwamba haiwezi fit ka kwamba watu wengi.

548
00:37:53,280 --> 00:37:58,250
Itakuwa tu kabisa overwrite char, ka 12 tumekuwa zilizotengwa kwa ajili yake,

549
00:37:58,250 --> 00:38:01,830
na kila kitu siku za nyuma katika kumbukumbu kwamba si kweli ni mali ya kwamba buffer

550
00:38:01,830 --> 00:38:06,520
na chochote kamba bar ni.

551
00:38:06,520 --> 00:38:09,780
Hiyo ilikuwa picha tuliona katika darasa

552
00:38:09,780 --> 00:38:12,220
ambapo tuna stack wetu kukua up.

553
00:38:12,220 --> 00:38:16,040
Unapaswa kutumika picha hizi au kupata familiar pamoja nao tena.

554
00:38:16,040 --> 00:38:21,260
Sisi stack wetu kupanda juu, anwani kumbukumbu kuanza saa 0 juu

555
00:38:21,260 --> 00:38:26,270
na kukua chini ya kama bilioni 4 chini.

556
00:38:26,270 --> 00:38:28,820
Tuna safu yetu 'c' mahali fulani katika kumbukumbu,

557
00:38:28,820 --> 00:38:32,260
basi tuna pointer yetu bar haki chini yake,

558
00:38:32,260 --> 00:38:38,720
na kisha tuna hii kuokolewa frame pointer katika kurudi anwani yetu na stack mzazi wetu mara kwa mara ya.

559
00:38:38,720 --> 00:38:40,800
Kumbuka yale kurudi anwani ni?

560
00:38:40,800 --> 00:38:45,360
Ni wakati kuu wito kazi foo, wito bar kazi,

561
00:38:45,360 --> 00:38:48,100
inevitably, bar anarudi.

562
00:38:48,100 --> 00:38:52,610
Hivyo wakati bar anarudi, wanahitaji kujua kwamba ni kurejea foo kwamba wito yake.

563
00:38:52,610 --> 00:39:01,360
Hivyo kurudi anwani ni ya barua pepe ya kazi ambayo ina kurudi wakati kazi anarudi.

564
00:39:01,360 --> 00:39:05,830
sababu hiyo muhimu kwa buffer mashambulizi kufurika ni kwa sababu, conveniently,

565
00:39:05,830 --> 00:39:09,580
walaghai kama mabadiliko hayo kurudi anwani.

566
00:39:09,580 --> 00:39:14,950
Badala ya kurejea foo, mimi nina kwenda nyuma popote hacker anataka niende nyuma.

567
00:39:14,950 --> 00:39:17,760
Na, conveniently, ambapo hacker mara nyingi anataka kwenda nyuma

568
00:39:17,760 --> 00:39:22,400
ni mwanzo wa buffer kwamba sisi awali alikuwa.

569
00:39:22,400 --> 00:39:26,170
Hivyo taarifa, tena, Little ya Hindi.

570
00:39:26,170 --> 00:39:28,490
appliance ni mfano wa Little Hindi mfumo,

571
00:39:28,490 --> 00:39:34,140
hivyo integer au pointer ni kuhifadhiwa na ka kuachwa.

572
00:39:34,140 --> 00:39:38,980
Kwa hiyo hapa tunaona - ni hii? Yeah.

573
00:39:38,980 --> 00:39:45,660
Tunaona Ox80, OxC0, Ox35, OxO8.

574
00:39:45,660 --> 00:39:48,250
Kumbuka tarakimu hexadesimoli?

575
00:39:48,250 --> 00:39:50,640
Hatuna kubadili tarakimu hexadesimoli katika kidogo ya Hindi,

576
00:39:50,640 --> 00:39:56,110
kwa sababu 2 hexadesimoli tarakimu kufanya juu ya byte moja, na sisi kubadili ka.

577
00:39:56,110 --> 00:40:00,300
Hiyo ni kwa nini sisi si kuhifadhi, kama, 80530CO8.

578
00:40:00,300 --> 00:40:07,520
Sisi kuhifadhi, badala yake, kila jozi ya tarakimu 2, kuanzia kulia.

579
00:40:07,520 --> 00:40:10,880
Anwani kwamba inahusu ya barua pepe ya kuanza

580
00:40:10,880 --> 00:40:15,190
ya buffer yetu kwamba sisi kweli alitaka nakala katika katika nafasi ya kwanza.

581
00:40:15,190 --> 00:40:19,230
sababu hiyo muhimu ni kwa sababu, nini kama mshambulizi

582
00:40:19,230 --> 00:40:24,100
kilichotokea kwa, badala ya kuwa string kwamba mara tu

583
00:40:24,100 --> 00:40:27,060
kamba wapole ya kama, majina yao au kitu,

584
00:40:27,060 --> 00:40:33,900
nini kama, badala yake, kamba waliokuwa baadhi tu ya code holela

585
00:40:33,900 --> 00:40:38,610
kwamba alifanya chochote walitaka kufanya?

586
00:40:38,610 --> 00:40:45,630
Ili waweze - Siwezi kufikiria ya maadili ya yoyote ya baridi.

587
00:40:45,630 --> 00:40:47,780
Inaweza kuwa kitu chochote, ingawa. Yoyote code mno.

588
00:40:47,780 --> 00:40:51,440
Kama walitaka, wangeweza tu kufanya kitu katika makosa seg, lakini hiyo haina maana.

589
00:40:51,440 --> 00:40:54,950
Kwa kawaida kufanya hivyo hack mfumo wako.

590
00:40:54,950 --> 00:40:59,930
>> Sawa. CS50 maktaba.

591
00:40:59,930 --> 00:41:04,800
Hii ni, kimsingi, GetInt, GetString, kazi wale wote sisi zinazotolewa kwa ajili yenu.

592
00:41:04,800 --> 00:41:10,630
Hivyo tuna * kamba char, na kwamba uchukuaji kwamba sisi akapiga mbali

593
00:41:10,630 --> 00:41:12,450
wakati fulani katika muhula.

594
00:41:12,450 --> 00:41:18,220
Kumbuka kwamba string ni safu ya wahusika.

595
00:41:18,220 --> 00:41:23,240
Kwa hiyo hapa tunaona toleo abridged ya GetString.

596
00:41:23,240 --> 00:41:25,920
Unapaswa kuangalia nyuma katika ni kukumbuka jinsi ni kweli kutekelezwa.

597
00:41:25,920 --> 00:41:30,950
Maelezo muhimu ni, taarifa sisi kupata katika tabia ya moja kwa wakati

598
00:41:30,950 --> 00:41:34,570
kutoka kiwango katika, ambayo ni tu kama sisi kuandika katika keyboard.

599
00:41:34,570 --> 00:41:37,890
Hivyo tabia moja kwa wakati mmoja, na kama sisi kupata wahusika wengi mno,

600
00:41:37,890 --> 00:41:40,580
hivyo kama n + 1 ni kubwa kuliko uwezo,

601
00:41:40,580 --> 00:41:44,140
basi tunahitaji kuongeza uwezo wa buffer yetu.

602
00:41:44,140 --> 00:41:47,780
Hivyo hapa sisi ni mara mbili ya ukubwa wa buffer yetu.

603
00:41:47,780 --> 00:41:51,840
Na kwamba anaendelea kwenda; sisi kuingiza tabia ndani ya buffer wetu

604
00:41:51,840 --> 00:41:56,220
mpaka tupewe line mpya au mwisho wa faili au chochote,

605
00:41:56,220 --> 00:41:59,380
katika kesi hiyo, sisi ni kosa kwa kamba na kisha GetString halisi

606
00:41:59,380 --> 00:42:05,120
akirudi kumbukumbu, kama kama sisi zilizotengwa kwa ajili ya kumbukumbu sana kutakuwa na kwenda nyuma na kuogopa kidogo.

607
00:42:05,120 --> 00:42:08,830
Hivyo hatuna kuonyesha kwamba, lakini wazo kuu ni

608
00:42:08,830 --> 00:42:11,960
ina kusoma katika tabia moja kwa wakati mmoja.

609
00:42:11,960 --> 00:42:17,140
Haiwezi kuwa tu kusoma katika jambo zima kwa mara moja,

610
00:42:17,140 --> 00:42:19,550
kwa sababu buffer yao ni tu ya ukubwa fulani.

611
00:42:19,550 --> 00:42:26,590
Hivyo kama kamba kwamba anajaribu kuingiza ndani ya buffer ni kubwa mno, basi itakuwa kufurika.

612
00:42:26,590 --> 00:42:28,940
Hivyo hapa sisi kuzuia kwamba kwa kusoma tu katika tabia moja

613
00:42:28,940 --> 00:42:33,750
wakati na kuongezeka kwa wakati wowote tunahitaji.

614
00:42:33,750 --> 00:42:40,270
Hivyo GetInt na wengine CS50 kazi maktaba huwa na kutumia GetString

615
00:42:40,270 --> 00:42:42,310
katika utekelezaji wao.

616
00:42:42,310 --> 00:42:45,370
Hivyo nilieleza mambo muhimu hapa.

617
00:42:45,370 --> 00:42:49,460
Ni wito GetString kupata kamba.

618
00:42:49,460 --> 00:42:51,710
Kama GetString alishindwa kurudi kumbukumbu,

619
00:42:51,710 --> 00:42:54,270
kukumbuka kwamba GetString mallocs kitu, hivyo wakati wewe piga GetString

620
00:42:54,270 --> 00:42:57,820
unapaswa (yasiyo na) bure kwamba kamba kwamba got.

621
00:42:57,820 --> 00:43:02,870
Hivyo hapa, kama alishindwa malloc kitu, sisi kurudi INT_MAX kama tu bendera kwamba,

622
00:43:02,870 --> 00:43:05,650
hey, sisi si walikuwa kweli na uwezo wa kupata integer.

623
00:43:05,650 --> 00:43:10,830
Unapaswa kupuuza chochote mimi kurudi kwenu, au

624
00:43:10,830 --> 00:43:15,540
unapaswa kutibu hii kama pembejeo halali.

625
00:43:15,540 --> 00:43:21,360
Hatimaye, kuchukua kwamba hakuwa kufanikiwa, sisi kutumia sscanf na kwamba bendera maalum,

626
00:43:21,360 --> 00:43:23,820
maana yake, kwanza mechi integer,

627
00:43:23,820 --> 00:43:26,770
kisha mechi wahusika yoyote baada ya hapo integer.

628
00:43:26,770 --> 00:43:29,070
Hivyo taarifa tunataka kwa sawa 1.

629
00:43:29,070 --> 00:43:32,940
Anarudi hivyo sscanf jinsi mechi nyingi kama mafanikio alifanya?

630
00:43:32,940 --> 00:43:37,010
Itakuwa kurudi 1 kama ni mafanikio kuendana integer,

631
00:43:37,010 --> 00:43:40,890
itakuwa kurudi 0 kama hakuwa na mechi integer, na atarudi 2

632
00:43:40,890 --> 00:43:45,920
kama kuendana integer na kufuatiwa na baadhi ya tabia.

633
00:43:45,920 --> 00:43:49,780
Hivyo taarifa sisi kujaribu tena kama sisi mechi kitu chochote lakini 1.

634
00:43:49,780 --> 00:43:55,230
Hivyo kama sisi aliingia 1, 2, 3, C, au 1, 2, 3, X,

635
00:43:55,230 --> 00:43:57,400
kisha 1, 2, 3 bila kupata kuhifadhiwa katika integer,

636
00:43:57,400 --> 00:43:59,620
X bila kupata kuhifadhiwa katika tabia,

637
00:43:59,620 --> 00:44:06,410
sscanf atarudi 2, na sisi ingekuwa kujaribu tena, kwa sababu sisi tu wanataka integer.

638
00:44:06,410 --> 00:44:09,810
>> Haraka kupiga kupitia HTML, HTTP, CSS.

639
00:44:09,810 --> 00:44:15,340
HyperText Markup Language ni muundo na semantiki ya mtandao.

640
00:44:15,340 --> 00:44:19,960
Hapa ni mfano kutoka hotuba ambapo tuna HTML.

641
00:44:19,960 --> 00:44:22,110
Tuna vitambulisho kichwa, vitambulisho mwili,

642
00:44:22,110 --> 00:44:27,770
tuna mifano ya vitambulisho tupu ambapo sisi kwa kweli hawana kuanza na tag karibu,

643
00:44:27,770 --> 00:44:30,820
sisi tu kiungo na picha.

644
00:44:30,820 --> 00:44:38,480
Hakuna kufunga picha tag; kuna tu tag moja ambayo kutimiza kila kitu tag anatakiwa kufanya.

645
00:44:38,480 --> 00:44:41,950
kiungo ni mfano, tutaweza kuona ni jinsi gani zilizounganishwa na CSS,

646
00:44:41,950 --> 00:44:45,910
script ni mfano wa jinsi zilizounganishwa na nje JavaScript.

647
00:44:45,910 --> 00:44:53,100
Ni pretty moja kwa moja, na kumbuka, HTML ni si lugha ya programu.

648
00:44:53,100 --> 00:44:58,250
Hapa, kumbuka jinsi gani kufafanua fomu au angalau kile huu bila kufanya?

649
00:44:58,250 --> 00:45:01,740
Fomu kama ina hatua na mbinu.

650
00:45:01,740 --> 00:45:06,210
mbinu wewe milele tu kuona ni GET na POST.

651
00:45:06,210 --> 00:45:09,040
Hivyo kupata ni toleo la ambapo kitu anapata kuweka katika URL.

652
00:45:09,040 --> 00:45:11,680
POST ni mahali ambapo si kuweka katika URL.

653
00:45:11,680 --> 00:45:18,520
Badala yake, data yoyote kutoka fomu ni kuingizwa siri zaidi katika ombi HTTP.

654
00:45:18,520 --> 00:45:22,390
Hivyo hapa, hatua amefafanua ambapo ombi HTTP unaendelea.

655
00:45:22,390 --> 00:45:27,490
Ambapo itakuja ni google.com / search.

656
00:45:27,490 --> 00:45:32,890
Method. Kumbuka tofauti kati ya GET na POST,

657
00:45:32,890 --> 00:45:37,200
na, kusema tu kama mfano, kama unataka alama kitu.

658
00:45:37,200 --> 00:45:40,660
Wewe kamwe kuwa na uwezo wa alama POST URL

659
00:45:40,660 --> 00:45:44,970
kwa sababu data si ni pamoja na katika URL.

660
00:45:44,970 --> 00:45:49,790
>> HTTP, sasa, ni HyperText Transfer Itifaki.

661
00:45:49,790 --> 00:45:54,080
HyperText Transfer Itifaki, bila kutarajia ni kuhamisha

662
00:45:54,080 --> 00:45:57,710
HyperText Markup Language, na ni gani.

663
00:45:57,710 --> 00:46:00,170
Lakini pia uhamisho picha yoyote kupata kwenye mtandao,

664
00:46:00,170 --> 00:46:05,400
downloads yoyote ya kufanya kuanza kama ombi HTTP.

665
00:46:05,400 --> 00:46:10,350
Hivyo HTTP ni lugha ya mtandao wa dunia nzima.

666
00:46:10,350 --> 00:46:15,610
Na hapa unahitaji kutambua aina hii ya ombi HTTP.

667
00:46:15,610 --> 00:46:19,300
Hapa HTTP/1.1 upande tu anasema kwamba toleo

668
00:46:19,300 --> 00:46:21,570
ya itifaki mimi nina kutumia.

669
00:46:21,570 --> 00:46:25,770
Ni pretty much daima itakuwa HTTP/1.1, kama utaona.

670
00:46:25,770 --> 00:46:30,110
Kisha sisi kuona kwamba hii ilikuwa GET, mbadala kuwa POST, kwamba unaweza kuona.

671
00:46:30,110 --> 00:46:40,790
Na URL kwamba mimi alikuwa anajaribu kutembelea mara www.google.com/search?q = blah, blah, blah.

672
00:46:40,790 --> 00:46:44,240
Basi kumbuka kwamba hii, alama swali q = blah blah blah,

673
00:46:44,240 --> 00:46:49,040
ni aina ya mambo ambayo ni kuwasilishwa kwa aina.

674
00:46:49,040 --> 00:46:51,830
majibu inaweza kurudi kwangu bila kuangalia kitu kama hiki.

675
00:46:51,830 --> 00:46:54,050
Tena, kwa kuanzia na itifaki, ambayo ni kwenda kuwa,

676
00:46:54,050 --> 00:46:59,190
ikifuatiwa na hali ya code. Hapa ni 200 sawa.

677
00:46:59,190 --> 00:47:05,060
Na hatimaye, ukurasa wa mtandao kwamba mimi kwa kweli aliuliza kwa zitafuatwa.

678
00:47:05,060 --> 00:47:08,210
iwezekanavyo hali ya code unaweza kuona, na unapaswa kujua kadhaa.

679
00:47:08,210 --> 00:47:12,770
200 OK wewe kuwa pengine kuona mbele.

680
00:47:12,770 --> 00:47:17,830
403 Haramu, 404 haionekani, Error 500 Ndani Server

681
00:47:17,830 --> 00:47:22,140
ni kawaida kama wewe kwenda kwenye tovuti na kitu ni kuvunjwa au shambulio yao PHP code,

682
00:47:22,140 --> 00:47:24,930
ambapo katika appliance tuna kuwa kubwa sanduku rangi ya machungwa

683
00:47:24,930 --> 00:47:27,830
kuja juu na kusema, kama, kuna kitu kibaya, kanuni hii haina kazi

684
00:47:27,830 --> 00:47:30,380
au kazi hii mbaya.

685
00:47:30,380 --> 00:47:33,230
Kawaida tovuti sitaki wewe kujua nini kazi ni kweli mbaya,

686
00:47:33,230 --> 00:47:37,880
hivyo badala wao itabidi tu kukupa 500 Ndani Makosa Server.

687
00:47:37,880 --> 00:47:43,050
>> TCP / IP ni 1 safu chini ya HTTP.

688
00:47:43,050 --> 00:47:47,550
Kumbuka kuwa kuna mtandao nje ya mtandao wa dunia nzima.

689
00:47:47,550 --> 00:47:52,270
Kama kama wewe kucheza mchezo online kwamba hana kupitia HTTP,

690
00:47:52,270 --> 00:47:55,740
ni kwenda kwa tofauti - ni bado kutumia mtandao,

691
00:47:55,740 --> 00:47:58,900
lakini haina matumizi HTTP.

692
00:47:58,900 --> 00:48:02,470
HTTP ni mfano mmoja tu wa itifaki umejengwa juu ya TCP / IP.

693
00:48:02,470 --> 00:48:07,820
IP maana yake halisi ni Itifaki ya mtandao.

694
00:48:07,820 --> 00:48:11,500
Kila kompyuta ina anwani ya IP; wao ni wale 4-tarakimu mambo

695
00:48:11,500 --> 00:48:16,510
kama 192.168.2.1, au chochote; kwamba huelekea kuwa moja ya ndani.

696
00:48:16,510 --> 00:48:23,390
Lakini hiyo ni mfano wa anwani ya IP.

697
00:48:23,390 --> 00:48:29,060
Hivyo DNS, Domain Jina Service,

698
00:48:29,060 --> 00:48:33,410
kwamba ni nini tafsiri ya mambo kama google.com kwa anwani halisi IP.

699
00:48:33,410 --> 00:48:37,700
Hivyo kama wewe aina hiyo IP katika URL,

700
00:48:37,700 --> 00:48:40,850
kwamba itakuwa kuleta kwa Google, lakini wewe huwa si kukumbuka mambo hayo.

701
00:48:40,850 --> 00:48:45,470
Wewe huwa na kumbuka google.com badala yake.

702
00:48:45,470 --> 00:48:51,560
Jambo la mwisho sisi ni bandari, ambapo hii ni TCP sehemu ya IP.

703
00:48:51,560 --> 00:48:54,880
TCP gani zaidi. Kufikiri juu, kama, unaweza kuwa na mtandao browser yako mbio.

704
00:48:54,880 --> 00:48:58,670
Labda una baadhi mbio email maombi;

705
00:48:58,670 --> 00:49:02,150
labda una baadhi ya mpango mwingine ambao hutumia mtandao mbio.

706
00:49:02,150 --> 00:49:05,090
Wote wanahitaji kupata mtandao,

707
00:49:05,090 --> 00:49:08,100
lakini kompyuta yako tu ina 1 WiFi kadi au chochote.

708
00:49:08,100 --> 00:49:10,780
Hivyo bandari ni njia ambayo sisi ni uwezo wa kupasuliwa up

709
00:49:10,780 --> 00:49:13,550
jinsi maombi hayo ni uwezo wa kutumia mtandao.

710
00:49:13,550 --> 00:49:17,230
Kila maombi anapata 1 maalum bandari kwamba unaweza kusikiliza juu,

711
00:49:17,230 --> 00:49:19,670
na kwa default, HTTP anatumia bandari 80.

712
00:49:19,670 --> 00:49:22,410
Baadhi ya huduma ya barua pepe kutumia 25.

713
00:49:22,410 --> 00:49:24,490
wale wa chini-kuhesabiwa huwa na kuwa zimehifadhiwa.

714
00:49:24,490 --> 00:49:29,270
Wewe ni kawaida na uwezo wa kupata wale juu-kuhesabiwa kwa mwenyewe.

715
00:49:29,270 --> 00:49:32,010
>> CSS, kuachia Style Sheets.

716
00:49:32,010 --> 00:49:36,030
Kurasa za mtandao sisi style na CSS, si kwa HTML.

717
00:49:36,030 --> 00:49:38,440
Kuna 3 maeneo unaweza kuweka CSS yako.

718
00:49:38,440 --> 00:49:46,300
Inaweza kuwa inline, kati ya vitambulisho style, au katika faili tofauti kabisa na kisha wanaohusishwa in

719
00:49:46,300 --> 00:49:48,470
Na hapa ni mfano tu wa CSS.

720
00:49:48,470 --> 00:49:50,450
Unapaswa kutambua muundo huu,

721
00:49:50,450 --> 00:49:54,310
ambapo mfano wa kwanza ni sisi ni vinavyolingana tag mwili,

722
00:49:54,310 --> 00:49:56,680
na hapa sisi ni centering tag mwili.

723
00:49:56,680 --> 00:50:00,420
mfano wa pili, sisi ni vinavyolingana kitu

724
00:50:00,420 --> 00:50:04,740
na ID footer, na sisi ni kuomba baadhi ya mitindo hiyo.

725
00:50:04,740 --> 00:50:07,310
Taarifa kwamba ID footer Nakala aligns-wa kushoto,

726
00:50:07,310 --> 00:50:09,840
ambapo mwili text-aligns kituo hicho.

727
00:50:09,840 --> 00:50:13,180
Footer ni ndani ya mwili.

728
00:50:13,180 --> 00:50:16,470
Itakuwa, badala yake, text-align kushoto, ingawa mwili anasema kituo hicho text-align.

729
00:50:16,470 --> 00:50:18,880
Hii ni zima kuachia sehemu yake.

730
00:50:18,880 --> 00:50:22,110
Unaweza kuwa na - unaweza bayana mitindo kwa mwili,

731
00:50:22,110 --> 00:50:25,320
na kisha mambo katika mwili unaweza bayana mitindo mahsusi zaidi,

732
00:50:25,320 --> 00:50:28,160
na mambo ya kazi kama wewe kutarajia.

733
00:50:28,160 --> 00:50:34,420
Specifiers zaidi maalum CSS fuatilia.

734
00:50:34,420 --> 00:50:46,140
Nadhani hiyo ni yake.

735
00:50:46,140 --> 00:50:49,260
>> [Ali Nahm] Hi kila mtu. Kama mimi naweza tu kupata mawazo yako.

736
00:50:49,260 --> 00:50:53,990
Mimi nina Ali na mimi nina kwenda kupitia PHP na SQL kweli haraka.

737
00:50:53,990 --> 00:51:00,310
Ili tuweze kuanza. PHP ni short kwa PHP: HyperText Preprocessor.

738
00:51:00,310 --> 00:51:03,730
Na kama wewe wote wanapaswa kujua, ni server-upande lugha scripting,

739
00:51:03,730 --> 00:51:06,800
na sisi kutumia kwa ajili ya mwisho ya nyuma ya Nje,

740
00:51:06,800 --> 00:51:12,540
na jinsi gani mengi ya computations, nyuma ya pazia sehemu.

741
00:51:12,540 --> 00:51:17,510
Syntax. Siyo kama C, mshangao, mshangao.

742
00:51:17,510 --> 00:51:22,060
Daima ina kuanza na, kama unaweza kuona, - Siwezi kusonga mbele.

743
00:51:22,060 --> 00:51:31,340
Unaweza kuona unahitaji aina mpya ya braces na kisha unahitaji pia? Php.

744
00:51:31,340 --> 00:51:35,780
Hiyo ni daima jinsi una sura PHP wako wa maandishi, PHP code yako.

745
00:51:35,780 --> 00:51:39,180
Hivyo haiwezi tu kuwa kama C, ambapo aina ya kuiweka juu ya kwanza.

746
00:51:39,180 --> 00:51:42,290
Unahitaji daima Surround yake.

747
00:51:42,290 --> 00:51:47,610
Na sasa, syntax kubwa ni kwamba vigezo vyote haja ya kuanza kwa $ tabia.

748
00:51:47,610 --> 00:51:49,490
Wewe haja ya kufanya hivyo wakati wewe ni kufafanua yao, unahitaji kufanya hivyo

749
00:51:49,490 --> 00:51:51,860
wakati wewe ni akimaanisha kwao baadaye.

750
00:51:51,860 --> 00:51:56,510
Daima haja ya $ hiyo. Ni rafiki yako mpya bora, pretty much.

751
00:51:56,510 --> 00:52:01,690
Huwezi - tofauti na C, huna haja ya kuweka aina gani ya kutofautiana aina ni.

752
00:52:01,690 --> 00:52:04,940
Hivyo wakati huna haja ya $, huna haja ya kuweka, kama,

753
00:52:04,940 --> 00:52:09,470
int x au kamba y, nakadhalika, nakadhalika.

754
00:52:09,470 --> 00:52:11,490
Hivyo tofauti kidogo.

755
00:52:11,490 --> 00:52:15,590
Kama matokeo ya hili, maana yake ni kwamba PHP ni aina weakly.

756
00:52:15,590 --> 00:52:19,310
PHP ni weakly lugha aina, na ina weakly typed vigezo.

757
00:52:19,310 --> 00:52:24,020
Kwa maneno mengine, hiyo ina maana kwamba unaweza kubadili kati ya aina tofauti ya aina ya kutofautiana.

758
00:52:24,020 --> 00:52:27,230
Unaweza kuhifadhi namba yako ya 1 kama int,

759
00:52:27,230 --> 00:52:29,650
unaweza kuhifadhi kama kamba, na unaweza kuhifadhi kama kuelea,

760
00:52:29,650 --> 00:52:33,550
na yote itakuwa kwamba idadi 1.

761
00:52:33,550 --> 00:52:36,080
Hata kama wewe ni hifadhi hiyo katika aina mbalimbali,

762
00:52:36,080 --> 00:52:39,120
bado ni - aina variable bado ni kufanya katika mwisho.

763
00:52:39,120 --> 00:52:41,540
Hivyo kama wewe kuangalia hapa, kama unakumbuka kutoka pset 7,

764
00:52:41,540 --> 00:52:43,500
wengi wenu pengine alikuwa na masuala na hili.

765
00:52:43,500 --> 00:52:47,280
Mbili ishara sawa, 3 ishara sawa, ishara 4 sawa.

766
00:52:47,280 --> 00:52:49,990
Sawa, hakuna dalili 4 sawa, lakini kuna 2 na 3.

767
00:52:49,990 --> 00:52:53,320
Unaweza kutumia 2 ishara sawa na kuangalia maadili.

768
00:52:53,320 --> 00:52:55,830
Ni unaweza kuangalia katika aina.

769
00:52:55,830 --> 00:52:58,770
Hivyo kama unaweza kuona katika mfano wa kwanza,

770
00:52:58,770 --> 00:53:02,210
Nina num_int == num_string.

771
00:53:02,210 --> 00:53:06,710
Hivyo int yako na kamba yako ni wawili, kitaalam, 1,

772
00:53:06,710 --> 00:53:10,790
lakini wao ni aina mbalimbali. Lakini kwa usawa mara mbili, kutakuwa na bado kupita.

773
00:53:10,790 --> 00:53:15,510
Hata hivyo, kwa usawa tatu, ni hundi thamani kama vile aina mbalimbali.

774
00:53:15,510 --> 00:53:18,760
Hiyo ina maana kwamba siyo kwenda kupita katika kesi ya pili hapa,

775
00:53:18,760 --> 00:53:22,350
ambapo unatumia 3 ishara sawa badala yake.

776
00:53:22,350 --> 00:53:26,590
Hivyo hiyo ni tofauti kubwa kwamba lazima wote umeonyesha sasa.

777
00:53:26,590 --> 00:53:31,570
>> Kamba concatenation ni kitu kingine nguvu unaweza kutumia katika PHP.

778
00:53:31,570 --> 00:53:34,080
Ni kimsingi tu hii Handy dot nukuu,

779
00:53:34,080 --> 00:53:36,230
na kwamba ni jinsi gani inaweza kumfunga masharti pamoja.

780
00:53:36,230 --> 00:53:40,800
Hivyo kama una Cat na una Dog, na unataka kuweka 2 masharti pamoja,

781
00:53:40,800 --> 00:53:44,080
unaweza kutumia kipindi, na hiyo ni aina ya jinsi kazi.

782
00:53:44,080 --> 00:53:46,660
Unaweza pia tu kuwaweka karibu na kila mmoja,

783
00:53:46,660 --> 00:53:49,030
kama unaweza kuona hapa katika mfano chini,

784
00:53:49,030 --> 00:53:51,610
ambapo nina echo string 1, nafasi string 2.

785
00:53:51,610 --> 00:53:56,930
PHP kujua nafasi yao kama vile.

786
00:53:56,930 --> 00:53:59,780
Arrays. Sasa, katika PHP, kuna 2 aina mbalimbali za arrays.

787
00:53:59,780 --> 00:54:03,180
Unaweza kuwa na arrays mara kwa mara, na unaweza pia kuwa na arrays associative,

788
00:54:03,180 --> 00:54:06,040
na sisi ni kwenda njia ya haki yao sasa.

789
00:54:06,040 --> 00:54:08,280
Mara kwa mara na arrays ni haki hii katika C,

790
00:54:08,280 --> 00:54:11,240
na hivyo kuwa fahirisi kwamba zinahesabika.

791
00:54:11,240 --> 00:54:13,160
Hivi sasa tuko tu kwenda kujenga moja na kuweka -

792
00:54:13,160 --> 00:54:15,500
hivyo hii ni jinsi sisi kujenga safu tupu, kisha tunakwenda

793
00:54:15,500 --> 00:54:17,310
kuweka katika index namba 0.

794
00:54:17,310 --> 00:54:19,200
Sisi ni kwenda kuweka namba 6, thamani 6.

795
00:54:19,200 --> 00:54:21,500
Unaweza kuona chini hapa.

796
00:54:21,500 --> 00:54:24,240
Where's - katika index namba 1 tunakwenda kuweka thamani namba 4,

797
00:54:24,240 --> 00:54:26,720
na hivyo unaweza kuona kuna 6, kuna 4,

798
00:54:26,720 --> 00:54:29,160
na kisha kama sisi ni uchapishaji mambo,

799
00:54:29,160 --> 00:54:33,550
wakati sisi kujaribu na magazeti thamani kuhifadhiwa katika index namba 0,

800
00:54:33,550 --> 00:54:36,900
kisha tutaweza kuona thamani 6 kuwa kuchapishwa. Cool?

801
00:54:36,900 --> 00:54:40,160
Hivyo kwamba ni arrays mara kwa mara kwa ajili yenu.

802
00:54:40,160 --> 00:54:42,750
Njia nyingine unaweza pia kuongeza mambo ya arrays mara kwa mara sasa

803
00:54:42,750 --> 00:54:44,780
ni unaweza tu append yao mwishoni.

804
00:54:44,780 --> 00:54:47,240
Hiyo ina maana kwamba huna kutaja maalum index.

805
00:54:47,240 --> 00:54:51,000
Unaweza kuona idadi, na kisha katika mabano mraba hakuna index maalum.

806
00:54:51,000 --> 00:54:56,270
Na itakuwa kujua - PHP kujua tu kuongeza hadi mwisho wa orodha, karibu bure doa.

807
00:54:56,270 --> 00:54:59,190
Hivyo unaweza kuona 1 haki pale katika kwamba 0 doa,

808
00:54:59,190 --> 00:55:02,690
2 akaenda haki pale katika doa kwanza.

809
00:55:02,690 --> 00:55:04,690
3 huenda - ni aliongeza huko pia.

810
00:55:04,690 --> 00:55:06,720
Ili aina ya hufanya akili. Wewe tu mara kwa mara na kuongeza kuwa,

811
00:55:06,720 --> 00:55:09,360
na kisha wakati sisi ni akirejea ripoti ya namba 1,

812
00:55:09,360 --> 00:55:13,080
itakuwa magazeti nje thamani 2.

813
00:55:13,080 --> 00:55:16,800
>> Kisha sisi na arrays kwamba ni arrays associative.

814
00:55:16,800 --> 00:55:19,370
Arrays associative, badala ya kuwa fahirisi namba,

815
00:55:19,370 --> 00:55:23,630
wanachokifanya ni, wana fahirisi kwamba ni kwa kamba.

816
00:55:23,630 --> 00:55:25,670
Unaweza kuona, badala ya - I got kuondoa wale wote fahirisi posta,

817
00:55:25,670 --> 00:55:32,140
na sasa ni key1, key2, key3, na wao uko katika quotes mbili kwa ishara ya kwamba wao ni masharti yote.

818
00:55:32,140 --> 00:55:34,470
Ili tuweze kuwa na mfano wa hii.

819
00:55:34,470 --> 00:55:38,790
Mfano wa hili ni kwamba tuna tf, na kwamba jina index.

820
00:55:38,790 --> 00:55:42,030
Sisi ni kwenda kuweka "Ali" kama jina, katika index, kalori kuliwa,

821
00:55:42,030 --> 00:55:47,640
tunaweza kuweka int wakati huu badala ya kamba,

822
00:55:47,640 --> 00:55:52,240
na kisha index anapenda, tunaweza kuweka safu nzima ndani yake.

823
00:55:52,240 --> 00:55:55,490
Hivyo hii ni aina ya - ni sawa na dhana ya jinsi tulikuwa

824
00:55:55,490 --> 00:55:58,930
fahirisi na idadi, lakini sasa tunaweza kubadili fahirisi karibu

825
00:55:58,930 --> 00:56:03,890
kuwa nao kama masharti badala yake.

826
00:56:03,890 --> 00:56:06,070
Unaweza pia kufanya hivyo, badala ya tu kufanya hivyo mmoja mmoja,

827
00:56:06,070 --> 00:56:09,400
unaweza kufanya yote katika chunk moja. Hivyo unaweza kuona kwamba tf ya kwamba safu,

828
00:56:09,400 --> 00:56:13,350
na kisha sisi kuweka watu wote katika moja kubwa za mraba mabano kuweka.

829
00:56:13,350 --> 00:56:15,220
Hivyo kwamba wanaweza kasi ya mambo up.

830
00:56:15,220 --> 00:56:19,730
Ni zaidi ya uchaguzi Stylistic kuliko hivyo.

831
00:56:19,730 --> 00:56:21,550
Sisi pia kuwa matanzi.

832
00:56:21,550 --> 00:56:26,020
Katika C tuna matanzi kwamba kazi kama hii.

833
00:56:26,020 --> 00:56:29,690
Tulikuwa na safu yetu, na sisi akaenda kutoka index 0 hadi mwisho wa orodha,

834
00:56:29,690 --> 00:56:31,740
na sisi magazeti yote, sawa?

835
00:56:31,740 --> 00:56:33,880
Ila tatizo ni, kwa associative arrays,

836
00:56:33,880 --> 00:56:36,610
sisi si lazima kujua fahirisi wale namba

837
00:56:36,610 --> 00:56:39,610
kwa sababu sasa tuna fahirisi kamba.

838
00:56:39,610 --> 00:56:44,800
Sasa sisi kutumia foreach tanzi, ambayo, tena, hopefully kutumika katika pset 7.

839
00:56:44,800 --> 00:56:48,930
Foreach loops tu kujua kila sehemu moja ya orodha.

840
00:56:48,930 --> 00:56:52,450
Na haina kujua hasa index namba kwamba wewe.

841
00:56:52,450 --> 00:56:56,490
Hivyo kuwa foreach syntax, hivyo ni foreach, kuweka safu.

842
00:56:56,490 --> 00:57:00,430
Hivyo safu yangu inaitwa pset, na kisha kama, neno kama,

843
00:57:00,430 --> 00:57:04,530
na kisha kuweka variable hii mitaa muda kwamba wewe ni kwenda kutumia

844
00:57:04,530 --> 00:57:10,690
tu kwa ajili ya kitu maalum kwamba kinaendelea kushikilia maalum -

845
00:57:10,690 --> 00:57:14,770
mfano moja au sehemu moja ya safu.

846
00:57:14,770 --> 00:57:18,350
Pset num kushikilia 1, na kisha labda ni kushikilia namba 6,

847
00:57:18,350 --> 00:57:20,410
na kisha kushikilia namba 2.

848
00:57:20,410 --> 00:57:26,630
Lakini ni uhakika kupitia kila thamani moja kwamba katika safu.

849
00:57:26,630 --> 00:57:30,530
Kazi muhimu ambayo unapaswa kujua katika PHP ni kuhitaji,

850
00:57:30,530 --> 00:57:35,880
hivyo kwamba inafanya uhakika kuwa wewe ni ikiwa ni pamoja na baadhi ya files, echo, exit, tupu.

851
00:57:35,880 --> 00:57:40,490
Mimi sana kupendekeza ukiangalia pset 7 na kuangalia kazi hizo.

852
00:57:40,490 --> 00:57:42,810
Unaweza kuwa na kujua hizo,

853
00:57:42,810 --> 00:57:47,060
hivyo napenda dhahiri kujua nini, hasa, wale wote kufanya.

854
00:57:47,060 --> 00:57:50,080
>> Na sasa sisi ni kwenda kupitia wigo kweli haraka.

855
00:57:50,080 --> 00:57:53,490
Kwa upeo, PHP ni aina ya kitu funky, tofauti na C,

856
00:57:53,490 --> 00:57:56,170
na hivyo sisi ni kwenda tu kwenda kwa njia hiyo haraka.

857
00:57:56,170 --> 00:57:58,930
Basi hebu kusema sisi kuanza saa mshale kwamba tuna huko.

858
00:57:58,930 --> 00:58:02,900
Na sisi ni kwenda kuanza na $ i. Hivyo variable 'i' ni kwenda 0,

859
00:58:02,900 --> 00:58:06,730
na sisi ni kwenda tu kuweka uchapishaji ni katika kuwa nyeupe kubwa sanduku zaidi ya hapo.

860
00:58:06,730 --> 00:58:09,220
Sisi ni kwenda kuanza na i0, na kisha tunakwenda kurudia yake.

861
00:58:09,220 --> 00:58:12,670
Hivyo kuna 0.

862
00:58:12,670 --> 00:58:15,210
Na kisha tunakwenda nyongeza ni kwa ajili ya kitanzi,

863
00:58:15,210 --> 00:58:17,810
na kisha kwenda kuwa thamani ya 1.

864
00:58:17,810 --> 00:58:20,070
Moja ni chini ya 3, hivyo kwenda kupita kwamba kwa kitanzi,

865
00:58:20,070 --> 00:58:23,230
na kisha tunakwenda kuona kuchapishwa tena.

866
00:58:23,230 --> 00:58:25,520
Tunakwenda nyongeza tena kwa 2,

867
00:58:25,520 --> 00:58:29,860
na 2 ni chini ya 3, hivyo itabidi kupita kwa kitanzi, na kutakuwa na magazeti 2.

868
00:58:29,860 --> 00:58:35,100
Basi itabidi kumbuka kuwa 3 ni si chini ya 3, hivyo tutaweza kuvunja nje ya kwa kitanzi.

869
00:58:35,100 --> 00:58:40,050
Hivyo sasa tumekuwa exited, na kisha sisi ni kwenda katika aFunction.

870
00:58:40,050 --> 00:58:45,010
Sawa. Hivyo kuwa na kumbuka kuwa kutofautiana hii tumeunda,

871
00:58:45,010 --> 00:58:48,270
'I' variable, si ndani ya nchi scoped.

872
00:58:48,270 --> 00:58:50,280
Hiyo ina maana kwamba siyo ndani kitanzi,

873
00:58:50,280 --> 00:58:58,060
na kwamba variable bado tunaweza kupata na mabadiliko ya baadaye, na bado kuwa na ufanisi.

874
00:58:58,060 --> 00:59:02,160
Hivyo kama wewe kwenda katika kazi sasa, utaona kwamba sisi pia kutumia 'i' variable,

875
00:59:02,160 --> 00:59:05,320
na tunakwenda nyongeza 'i' + +.

876
00:59:05,320 --> 00:59:09,410
Unaweza kudhani, kwa mara ya kwanza, kwa kuzingatia C, kwamba nakala ya 'i' kutofautiana.

877
00:59:09,410 --> 00:59:12,830
Ni jambo tofauti kabisa, ambayo ni sahihi.

878
00:59:12,830 --> 00:59:16,560
Hivyo wakati sisi magazeti hayo, tunakwenda magazeti 'i' + +, ambayo ni kwenda magazeti kuwa 4,

879
00:59:16,560 --> 00:59:19,640
na kisha tunakwenda - sorry.

880
00:59:19,640 --> 00:59:22,030
Kisha tunakwenda mwisho nje ya kazi hiyo,

881
00:59:22,030 --> 00:59:24,820
na tunakwenda kuwa na ambapo mshale ni hivi sasa.

882
00:59:24,820 --> 00:59:29,190
Hiyo ina maana kwamba huo, hata hivyo, ingawa kazi iliyopita thamani ya 'i',

883
00:59:29,190 --> 00:59:32,620
hakuwa na kubadili nje ya kazi,

884
00:59:32,620 --> 00:59:35,060
kwa sababu kazi ina wigo tofauti.

885
00:59:35,060 --> 00:59:38,960
Hiyo ina maana kwamba wakati sisi echo 'i', ina si iliyopita katika wigo wa kazi,

886
00:59:38,960 --> 00:59:43,660
na hivyo basi tunakwenda magazeti 3 tena.

887
00:59:43,660 --> 00:59:47,520
Mambo mbalimbali juu ya mipaka katika PHP kuliko katika C.

888
00:59:47,520 --> 00:59:51,130
>> Sasa katika PHP na HTML.

889
00:59:51,130 --> 00:59:53,510
PHP ni kutumika kufanya kurasa za mtandao nguvu.

890
00:59:53,510 --> 00:59:58,660
Ni aina ya hufanya mambo mbalimbali.

891
00:59:58,660 --> 01:00:02,090
Tuna ni tofauti na HTML.

892
01:00:02,090 --> 01:00:05,230
Kwa HTML, sisi daima tu kuwa sawa tuli kitu, kama jinsi Rob ilionyesha,

893
01:00:05,230 --> 01:00:09,370
ambapo PHP, unaweza kubadilisha mambo msingi ambao user ni.

894
01:00:09,370 --> 01:00:11,830
Basi, ikiwa mimi na huu, mimi, "Wewe ni watumiaji katika kama -" na kisha jina,

895
01:00:11,830 --> 01:00:14,420
na Mimi naweza kubadili jina. Hivyo sasa hivi jina ni Joseph,

896
01:00:14,420 --> 01:00:18,880
na ina "kuhusu mimi," lakini naweza pia kubadili jina kuwa na Tommy.

897
01:00:18,880 --> 01:00:21,700
Na kwamba itakuwa ni jambo tofauti.

898
01:00:21,700 --> 01:00:23,840
Hivyo tunaweza pia kubadili mambo mbalimbali juu yake,

899
01:00:23,840 --> 01:00:27,070
na itakuwa kuonyesha bidhaa tofauti kulingana na jina.

900
01:00:27,070 --> 01:00:31,430
Hivyo PHP unaweza aina ya kubadili nini kinaendelea katika tovuti yako.

901
01:00:31,430 --> 01:00:33,540
Same hapa. Hata hivyo, kumbuka kwamba wao kuwa na maudhui tofauti,

902
01:00:33,540 --> 01:00:38,870
hata kama wewe ni utaalamu bado kupata mtandao huo ukurasa kwamba juu ya uso.

903
01:00:38,870 --> 01:00:43,450
Kuzalisha HTML. Kuna njia 2 mbalimbali ambazo unaweza kufanya hivyo.

904
01:00:43,450 --> 01:00:48,980
Hivyo tutaweza kwenda kwa kuwa hivi sasa. Njia ya kwanza ni, una - yeah, sorry.

905
01:00:48,980 --> 01:00:51,150
Hivyo tu na mara kwa mara yako kwa kitanzi katika PHP,

906
01:00:51,150 --> 01:00:56,270
na kisha echo katika PHP na echo nje HTML.

907
01:00:56,270 --> 01:00:58,720
Kutumia kile Rob ilionyesha yenu ya HTML script

908
01:00:58,720 --> 01:01:04,030
na kisha kwa kutumia PHP magazeti tu magazeti ya nje kwa ukurasa wa mtandao.

909
01:01:04,030 --> 01:01:09,520
njia mbadala ni kufanya hivyo kama wewe tofauti nje PHP na HTML.

910
01:01:09,520 --> 01:01:11,940
Hivyo unaweza kuwa mstari wa PHP kwamba kuanza kwa kitanzi,

911
01:01:11,940 --> 01:01:16,020
basi unaweza kuwa mstari wa HTML katika kitu tofauti,

912
01:01:16,020 --> 01:01:19,700
na kisha mwisho kitanzi, tena, na PHP.

913
01:01:19,700 --> 01:01:21,800
Hivyo ni aina ya kutenganisha nje.

914
01:01:21,800 --> 01:01:24,020
Upande wa kushoto, unaweza kuwa una wote -

915
01:01:24,020 --> 01:01:26,360
ni 1 tu chunk ya PHP.

916
01:01:26,360 --> 01:01:28,510
Juu ya haki unaweza kuona kwamba una mstari wa PHP,

917
01:01:28,510 --> 01:01:32,540
una mstari wa HTML, na una mstari wa PHP tena.

918
01:01:32,540 --> 01:01:36,870
Hivyo kutenganisha ni nje katika waliyo ni kufanya.

919
01:01:36,870 --> 01:01:39,330
Na wewe utakuwa kumbuka kuwa aidha njia, kwa aidha wao,

920
01:01:39,330 --> 01:01:41,980
wao bado magazeti nje ya picha, picha, picha,

921
01:01:41,980 --> 01:01:44,540
ili HTML bado ni kuchapishwa njia hiyo hiyo.

922
01:01:44,540 --> 01:01:49,870
Na kisha bado utaona 3 images show up kwenye tovuti yako.

923
01:01:49,870 --> 01:01:52,820
Hivyo ni njia 2 mbalimbali ya kufanya kitu kimoja.

924
01:01:52,820 --> 01:01:55,060
>> Sasa tuna aina na maombi. Kama Rob ilionyesha wewe,

925
01:01:55,060 --> 01:01:59,400
kuna aina ya HTML, na sisi tu breeze kwa njia hii.

926
01:01:59,400 --> 01:02:02,040
Una hatua na una mbinu, na hatua yako

927
01:02:02,040 --> 01:02:04,350
aina ya inaonyesha wapi utaenda kutuma, na njia ni kama

928
01:02:04,350 --> 01:02:06,960
ni kwenda kuwa GET au POST.

929
01:02:06,960 --> 01:02:11,220
Na ombi GET, kama Rob akasema, ina maana kwamba ni kwenda kuweka katika fomu

930
01:02:11,220 --> 01:02:15,760
na utaona kama URL, ambapo ombi POST huwezi kuona katika URL.

931
01:02:15,760 --> 01:02:17,840
Hivyo tofauti kidogo.

932
01:02:17,840 --> 01:02:19,950
Hata hivyo, jambo moja kwamba jambo kama hilo

933
01:02:19,950 --> 01:02:22,560
ni kwamba POST na GET ni sawa salama.

934
01:02:22,560 --> 01:02:26,430
Hivyo unaweza kufikiri kwamba kwa sababu tu huna kuona katika URL,

935
01:02:26,430 --> 01:02:28,790
hiyo ina maana POST ni salama zaidi,

936
01:02:28,790 --> 01:02:34,420
lakini bado unaweza kuona katika cookies zako katika taarifa kwamba wewe ni kutuma.

937
01:02:34,420 --> 01:02:38,260
Hivyo sidhani kuwa karibu moja au nyingine.

938
01:02:38,260 --> 01:02:42,160
Kitu kingine kukumbuka ni kwamba wewe pia kuwa na sehemu vigezo.

939
01:02:42,160 --> 01:02:45,850
You guys alitumia katika pset 7 kupata user ID habari yako.

940
01:02:45,850 --> 01:02:48,550
Ni nini kilichotokea ni kwamba unaweza kutumia safu hii associative,

941
01:02:48,550 --> 01:02:53,310
$ _SESSION, Na kisha uko na uwezo wa kupata mambo mbalimbali

942
01:02:53,310 --> 01:02:57,720
na kuhifadhi vitu mbalimbali katika kurasa.

943
01:02:57,720 --> 01:03:00,750
>> Jambo la mwisho ni kwamba tuna SQL, Uliza muundo lugha,

944
01:03:00,750 --> 01:03:04,360
na hii ni lugha ya programu ya kusimamia database.

945
01:03:04,360 --> 01:03:08,220
Nini, hasa, ni database? Wao ni makusanyo ya meza,

946
01:03:08,220 --> 01:03:10,630
na kila meza inaweza kuwa sawa aina ya vitu.

947
01:03:10,630 --> 01:03:14,990
Hivyo tulikuwa na meza ya watumiaji katika fedha pset yako.

948
01:03:14,990 --> 01:03:20,610
Na kwa nini wao muhimu? Kwa sababu ni njia ya kudumu ya kuhifadhi habari.

949
01:03:20,610 --> 01:03:22,840
Ni njia ya kufuatilia mambo na kusimamia mambo

950
01:03:22,840 --> 01:03:25,890
na kwa kweli kuona kwenye kurasa tofauti na kuweka wimbo.

951
01:03:25,890 --> 01:03:29,930
Wakati kama wewe tu kuhifadhi katika kwamba mtu mara moja wakati

952
01:03:29,930 --> 01:03:33,720
na kisha kutumia baadaye, huwezi kuwa na uwezo wa kupata kitu chochote wameweza kuokolewa.

953
01:03:33,720 --> 01:03:37,660
Tuna 4 mambo makubwa kwamba sisi kutumia kwa amri SQL.

954
01:03:37,660 --> 01:03:40,190
Tuna kuchagua, kuingiza, kufuta, na update.

955
01:03:40,190 --> 01:03:42,880
Wale ni kweli ni muhimu kwa nyie kujua kwa jaribio yako.

956
01:03:42,880 --> 01:03:45,990
>> Tutaweza haraka kwenda juu ya haki ya kuchagua sasa.

957
01:03:45,990 --> 01:03:48,540
Kimsingi, wewe ni kuchagua safu kutoka database.

958
01:03:48,540 --> 01:03:52,400
Hivyo kama una, haki hapa -

959
01:03:52,400 --> 01:03:56,740
tuna mambo haya 2 mbalimbali, na tunataka kuchagua kutoka madarasa meza

960
01:03:56,740 --> 01:04:01,480
ambapo kutisha - ambapo katika safu ya kutisha thamani ni 1.

961
01:04:01,480 --> 01:04:04,460
Hivyo unaweza kuona hapa, tuna mambo haya 2 ya jina darasa,

962
01:04:04,460 --> 01:04:08,490
CS50 na Stat110, na sisi na vitambulisho darasa na kauli mbiu.

963
01:04:08,490 --> 01:04:13,150
Hivyo tunataka kuchagua wote wa habari kwamba.

964
01:04:13,150 --> 01:04:17,480
Basi unaweza kuona haki hapa kwamba ni aina ya kuokota nje ya safu ya kwamba kutisha,

965
01:04:17,480 --> 01:04:25,170
ambapo mambo yote ni 1, na kisha ina darasa ID, jina darasa na kauli mbiu ya kwamba inaweza kuchukua nje.

966
01:04:25,170 --> 01:04:28,100
Jinsi gani hasa gani unaweza kufanya hili katika kanuni? Una kutumia PHP.

967
01:04:28,100 --> 01:04:33,830
Basi hiyo ni aina ya jinsi PHP na SQL ni kuhusiana na kila mmoja.

968
01:04:33,830 --> 01:04:38,130
Sasa tuna kanuni zetu, na sisi ni kwenda kutumia swala yetu kufanya kazi

969
01:04:38,130 --> 01:04:41,370
kama tulivyofanya katika pset 7, na sisi ni kwenda kukimbia SQL query.

970
01:04:41,370 --> 01:04:43,870
Kisha tunakwenda na -

971
01:04:43,870 --> 01:04:46,280
sisi daima kuwa na kuangalia kama mstari wa tatu sawa kama uongo.

972
01:04:46,280 --> 01:04:49,010
Hivyo tena, unataka kuangalia aina na thamani,

973
01:04:49,010 --> 01:04:53,880
na kisha kama hana kazi, basi unataka kuomba msamaha, kama kawaida, kama tulivyofanya katika pset 7.

974
01:04:53,880 --> 01:04:55,870
Vinginevyo, unataka kitanzi kwa njia ya kila kitu na wale Handy

975
01:04:55,870 --> 01:04:59,410
foreach matanzi kwamba sisi tu alikwenda juu.

976
01:04:59,410 --> 01:05:01,280
Sasa kwa kuwa sisi ni wanaoendesha kupitia na tumekuwa alifanya hivyo siku za nyuma,

977
01:05:01,280 --> 01:05:05,080
hebu kudhani kwamba swala zetu kupita, kwa sasa tuna foreach yetu kitanzi.

978
01:05:05,080 --> 01:05:11,050
Na safu ya kwanza ina, hivyo hapa ni mstari, haki hapa; ni boxed.

979
01:05:11,050 --> 01:05:14,010
Ni kwenda na magazeti nje taarifa zote kwamba wamezipata.

980
01:05:14,010 --> 01:05:18,070
Hivyo ni kwenda magazeti nje chini "Wanna Jifunze HTML?"

981
01:05:18,070 --> 01:05:23,370
Basi ni kwenda kwa mstari unaofuata, kwa sababu ni kukamilika kwanza kwa kitanzi,

982
01:05:23,370 --> 01:05:26,510
na hivyo basi ni kwenda magazeti nje line pili ya hayo,

983
01:05:26,510 --> 01:05:32,120
ambayo ni kwenda kuwa STAT110, kupata muda wote.

984
01:05:32,120 --> 01:05:34,290
>> Jambo la mwisho ni juu ya SQL Udhaifu.

985
01:05:34,290 --> 01:05:37,300
Mimi najua David kuguswa juu ya hii kidogo katika hotuba.

986
01:05:37,300 --> 01:05:40,730
Unaweza kusoma hii baadaye. Ni kweli funny.

987
01:05:40,730 --> 01:05:45,320
SQL sindano ni aina ya kitu gumu.

988
01:05:45,320 --> 01:05:49,890
Hebu kusema kwamba wewe tu fimbo vigezo wale haki katika hoja yako,

989
01:05:49,890 --> 01:05:52,290
kama unaweza kuona katika mstari wa kwanza.

990
01:05:52,290 --> 01:05:54,520
Hivyo inaonekana faini, sawa? Wewe ni kuweka tu katika jina la mtumiaji

991
01:05:54,520 --> 01:05:58,820
na password kwa SQL yako swala, na unataka meli hiyo mbali na kupata chochote ni katika meza yako data.

992
01:05:58,820 --> 01:06:01,450
Hiyo inaonekana kuwa rahisi. Kwa hiyo lets kusema mtu unaweka katika,

993
01:06:01,450 --> 01:06:04,910
kwa password, hii AU Nakala haki hapa -

994
01:06:04,910 --> 01:06:06,780
lazima kweli kuwa katika sanduku nyekundu.

995
01:06:06,780 --> 01:06:11,920
Basi hebu kusema kwamba wao kuweka neno la siri kwamba katika - kwamba ni nini wao kuingia.

996
01:06:11,920 --> 01:06:16,520
Basi ni kuweka AU "1" = 1.

997
01:06:16,520 --> 01:06:20,880
Aina ya password silly kuwa.

998
01:06:20,880 --> 01:06:25,070
Sasa hebu tu badala yake katika, na wewe utakuwa kumbuka kuwa katika SQL swala sasa,

999
01:06:25,070 --> 01:06:29,090
ni kutathmini kwa kweli daima, kwa sababu wewe utakuwa kumbuka kuwa

1000
01:06:29,090 --> 01:06:32,240
unaweza SQL swala kuchagua wote wa habari hii

1001
01:06:32,240 --> 01:06:35,420
au unaweza tu na 1 = 1.

1002
01:06:35,420 --> 01:06:41,030
Ili daima kwenda kutathmini kwa kweli.

1003
01:06:41,030 --> 01:06:46,610
Hiyo si kwenda kwa kweli kazi, kwa sababu hiyo ina maana kwamba hacker unaweza kuvunja katika mfumo wako.

1004
01:06:46,610 --> 01:06:49,300
ufumbuzi wa hili ni kwamba una kutumia mfumo wa PDO,

1005
01:06:49,300 --> 01:06:51,360
ambayo ina maana kwamba una kutumia alama ya swali,

1006
01:06:51,360 --> 01:06:53,350
ambayo ni nini guys kutumika katika pset 7,

1007
01:06:53,350 --> 01:06:57,620
wapi utaenda kutumia alama swali katika nafasi ya wapi unataka kuweka kitu,

1008
01:06:57,620 --> 01:07:01,430
na kisha utaenda na comma, na kisha itabidi baada ya hapo,

1009
01:07:01,430 --> 01:07:07,610
baada ya kamba yako, vigezo mbalimbali kwamba unataka kuchukua nafasi ya ndani yako alama ya swali.

1010
01:07:07,610 --> 01:07:10,330
Hivyo itabidi kukumbuka hapa kwamba sasa nina alama hizi nyekundu swali.

1011
01:07:10,330 --> 01:07:15,420
Kisha mimi kuweka vigezo baada ya masharti yangu ili niweze kujua nafasi yao ili baadaye.

1012
01:07:15,420 --> 01:07:18,470
Hiyo kuhakikisha kwamba kama mtu gani kama hii,

1013
01:07:18,470 --> 01:07:24,050
na wana au 1 = 1 hali hiyo, ambayo kuhakikisha,

1014
01:07:24,050 --> 01:07:30,490
mwisho nyuma, kuhakikisha kwamba si kweli kuvunja SQL query.

1015
01:07:30,490 --> 01:07:33,660
Sawa, hivyo kwamba ni pretty kiasi, kimbunga cha PHP na SQL.

1016
01:07:33,660 --> 01:07:41,520
Bora wa bahati nyote, na sasa Ore

1017
01:07:41,520 --> 01:07:44,270
>> [Oreoluwatomiwa Babarinsa] Sawa kila mtu. Muda wa kwenda juu ya baadhi ya JavaScript

1018
01:07:44,270 --> 01:07:48,840
na baadhi ya mambo mengine kwa haraka sana hivyo hatuna kushikilia wewe up usiku wa leo.

1019
01:07:48,840 --> 01:07:56,930
JavaScript. Ndiyo. JavaScript ni aina ya kitu baridi, purportedly.

1020
01:07:56,930 --> 01:07:59,090
mambo kweli unahitaji kujua kuhusu JavaScript, ni aina ya kama

1021
01:07:59,090 --> 01:08:03,810
mteja upande mwisho wa kile mtandao programu yako ni kwenda kufanya.

1022
01:08:03,810 --> 01:08:08,280
Kuna baadhi ya mambo tu hawataki kutunza muda wote juu ya upande server.

1023
01:08:08,280 --> 01:08:12,880
Mwingiliano kidogo zote, akielezea jambo moja, kufanya kitu kutoweka.

1024
01:08:12,880 --> 01:08:15,340
Wewe kweli hawataki kuzungumza na server yako wakati wote kwa ajili hiyo.

1025
01:08:15,340 --> 01:08:18,069
Na baadhi ya kwamba ni hata inawezekana kufanya upande wa server.

1026
01:08:18,069 --> 01:08:21,899
Hii ni kwa nini tunahitaji kitu kama JavaScript.

1027
01:08:21,899 --> 01:08:24,359
Mambo ya baridi kuhusu JavaScript: Ni dynamically typed.

1028
01:08:24,359 --> 01:08:27,149
Nini maana ya hii ni kwamba mpango wako haina haja ya kujua

1029
01:08:27,149 --> 01:08:30,970
nini, hasa, vigezo ni wakati kuandika nje.

1030
01:08:30,970 --> 01:08:34,510
Ni itabidi aina ya takwimu nje kama ni mbio.

1031
01:08:34,510 --> 01:08:37,520
Mambo mengine ambayo ni ya baridi kuhusu hilo: Ni curly lugha brace,

1032
01:08:37,520 --> 01:08:41,359
ambayo ina maana syntax ni sawa na C na PHP.

1033
01:08:41,359 --> 01:08:47,050
Huna kufanya rework sana wakati wewe ni kujifunza JavaScript.

1034
01:08:47,050 --> 01:08:49,180
Hapa tuna kidogo ya JavaScript.

1035
01:08:49,180 --> 01:08:52,560
Kuvutia jambo la haki hapa ni kwamba, kama ukiangalia hiyo,

1036
01:08:52,560 --> 01:08:56,330
sisi kuwa na kidogo ya JavaScript haki pale katika tag kichwa.

1037
01:08:56,330 --> 01:08:59,479
Je, ni gani kimsingi ni tu ni pamoja na JavaScript file.

1038
01:08:59,479 --> 01:09:02,260
Hii ni njia moja unaweza ni pamoja na JavaScript katika mpango wako.

1039
01:09:02,260 --> 01:09:06,910
Kisha pili kidogo ni kweli kuna baadhi ya inline JavaScript,

1040
01:09:06,910 --> 01:09:10,790
sawa na inline style na CSS,

1041
01:09:10,790 --> 01:09:16,180
na wewe ni kuandika tu baadhi ya kanuni haraka sana huko.

1042
01:09:16,180 --> 01:09:18,120
JavaScript ina arrays.

1043
01:09:18,120 --> 01:09:20,850
Tu njia nyingine ya kuweka data kote, muhimu sana.

1044
01:09:20,850 --> 01:09:25,180
Nzuri sana na rahisi syntax.

1045
01:09:25,180 --> 01:09:29,870
Unaweza kutumia mabano mraba ya kupata kila kitu na kuweka kila kitu pamoja.

1046
01:09:29,870 --> 01:09:35,020
Hakuna magumu mno.

1047
01:09:35,020 --> 01:09:38,630
jambo zuri kuhusu JavaScript na lugha scripting kwa ujumla

1048
01:09:38,630 --> 01:09:40,920
ni kwamba huna kuwa na wasiwasi kuhusu ukubwa safu.

1049
01:09:40,920 --> 01:09:43,880
Unaweza kutumia tu array.length na kuweka wimbo wa hivyo,

1050
01:09:43,880 --> 01:09:46,960
na pia safu unaweza kukua au kuogopa kama unahitaji kwa.

1051
01:09:46,960 --> 01:09:49,279
Hivyo huna hata haja ya kuwa na wasiwasi kuhusu aina yoyote ya,

1052
01:09:49,279 --> 01:09:57,050
oh no, mimi haja ya kutenga mambo mengi zaidi, au kitu kama hicho.

1053
01:09:57,050 --> 01:10:00,090
>> Jambo zuri hapa ni kwamba JavaScript ina kitu kinachoitwa vitu.

1054
01:10:00,090 --> 01:10:04,800
Ni kitu-oriented lugha, ili kile ina ni, kimsingi,

1055
01:10:04,800 --> 01:10:10,100
njia kwa ajili yenu kwa data kundi pamoja, kwa kiasi fulani sawa na struct,

1056
01:10:10,100 --> 01:10:17,280
lakini unaweza kupata ni kama struct au katika associative safu syntax.

1057
01:10:17,280 --> 01:10:22,520
Ni pretty rahisi na nini unaweza kufanya na hii ni data kundi pamoja

1058
01:10:22,520 --> 01:10:24,810
kama wewe kuwa na rundo la data hiyo kuhusiana.

1059
01:10:24,810 --> 01:10:26,850
Kwa sababu ni mambo yote unahitaji kuelezea gari,

1060
01:10:26,850 --> 01:10:29,050
huna haja ya kuwa ni katika kundi la maeneo mbalimbali.

1061
01:10:29,050 --> 01:10:35,300
Unaweza tu fimbo yake katika 1 kitu katika JavaScript.

1062
01:10:35,300 --> 01:10:39,090
Kama pengine kujua, iterating ni moja ya kazi hizo tedious.

1063
01:10:39,090 --> 01:10:43,810
Wewe tu kufanya hivyo juu ya tena. Unahitaji kuzungumza na kila kitu katika gari,

1064
01:10:43,810 --> 01:10:47,340
au haja ya kwenda kwa kila kitu katika orodha au kitu kama hicho.

1065
01:10:47,340 --> 01:10:51,770
Hivyo JavaScript ina, sawa na PHP, foreach syntax.

1066
01:10:51,770 --> 01:10:54,590
Katika kesi hiyo, ni kwa ajili ya katika kitanzi.

1067
01:10:54,590 --> 01:10:57,300
Unataka kutumia hii tu juu ya vitu.

1068
01:10:57,300 --> 01:11:01,030
Kuna baadhi ya matatizo kutokea kama wewe kutumia hii juu ya arrays.

1069
01:11:01,030 --> 01:11:03,750
Ni kwa ujumla ni moja ya mambo hayo, ingawa, kwamba ni muhimu sana,

1070
01:11:03,750 --> 01:11:06,590
kwa sababu wewe kuondoa mengi ya uendeshaji

1071
01:11:06,590 --> 01:11:10,270
kwa sababu huna kuvuta juu ya kila kitu katika kitu yako na wewe mwenyewe.

1072
01:11:10,270 --> 01:11:12,300
Huna kukumbuka majina yote muhimu.

1073
01:11:12,300 --> 01:11:18,270
Wewe tu aina ya kupata yao nyuma katika syntax hii.

1074
01:11:18,270 --> 01:11:21,500
Katika hili, na kwa ajili ya, wewe tu wanataka kukumbuka

1075
01:11:21,500 --> 01:11:27,180
kwamba wewe ni kupata nyuma funguo zote, katika njia sawa na hash meza.

1076
01:11:27,180 --> 01:11:30,880
Kama unakumbuka na kwamba, wakati bila kuweka katika kamba unaweza kupata kitu nje

1077
01:11:30,880 --> 01:11:33,840
kwamba ingekuwa kuhusishwa thamani nayo.

1078
01:11:33,840 --> 01:11:36,360
Nini unaweza kufanya na hii ni unaweza kusema, haki ya wote,

1079
01:11:36,360 --> 01:11:42,120
Mimi kuweka katika gari, na mimi kuitwa kuwa ni Ferrari.

1080
01:11:42,120 --> 01:11:45,290
Hivyo unaweza kuweka katika kamba Ferrari tena baadaye, na unaweza kupata kwamba nje.

1081
01:11:45,290 --> 01:11:50,000
Na unaweza kufanya hivyo katika kitanzi, na kwa katika kitanzi.

1082
01:11:50,000 --> 01:11:53,320
Hivyo tu zaidi kuhusu vitu. Jambo muhimu kutoka huu unahitaji kukumbuka

1083
01:11:53,320 --> 01:12:00,340
ni kwamba unaweza kutumia kitu struct kama syntax wakati wowote unataka na hayo,

1084
01:12:00,340 --> 01:12:04,590
isipokuwa kama yako kwenda kutumia kama kamba si halali jina kutofautiana.

1085
01:12:04,590 --> 01:12:07,650
Hivyo kama ukiangalia kwamba kuna, tuna muhimu kwa nafasi.

1086
01:12:07,650 --> 01:12:12,500
Naam, kama ungekuwa na kuweka object.key, nafasi, na, nafasi, nafasi,

1087
01:12:12,500 --> 01:12:15,320
kwamba tu bila ya kufanya maana syntactically.

1088
01:12:15,320 --> 01:12:22,730
Hivyo tu anaweza kufanya hivyo na aina hii ya bracket syntax.

1089
01:12:22,730 --> 01:12:26,520
>> Pia, JavaScript ni sana wigo-busara PHP.

1090
01:12:26,520 --> 01:12:29,050
Una 2 namna ya kushughulikia upeo.

1091
01:12:29,050 --> 01:12:31,960
Huwezi kuwa na var mbele ya kutofautiana,

1092
01:12:31,960 --> 01:12:34,060
na kwamba tu maana hii ni ya kimataifa.

1093
01:12:34,060 --> 01:12:37,050
Unaweza kuona kutoka mahali popote. Hata kama ungekuwa na kuweka hii katika kama taarifa,

1094
01:12:37,050 --> 01:12:42,430
mahali popote katika kanuni yako baada ya hatua hiyo unaweza kuona kwamba kutofautiana.

1095
01:12:42,430 --> 01:12:46,730
Jambo jingine, ingawa, ni kwa var, ni mdogo kwa chochote kazi ulimokuwa

1096
01:12:46,730 --> 01:12:48,870
Kama wewe si katika kazi, vizuri, ni duniani.

1097
01:12:48,870 --> 01:12:53,900
Lakini kama wewe ni katika kazi ni wazi tu ndani ya kazi hiyo.

1098
01:12:53,900 --> 01:12:56,420
Sina mfano, lakini, yeah. Ni moja ya mambo hayo ambapo

1099
01:12:56,420 --> 01:12:59,900
unaweza kusimamia nini vigezo unataka kuwa wa kimataifa,

1100
01:12:59,900 --> 01:13:03,810
nini vigezo unataka kuwa wa ndani, lakini huna haja ya kuwa makini kuhusu hili,

1101
01:13:03,810 --> 01:13:06,890
kwa sababu huna aina ya kudhibiti nafaka faini kufanya katika C,

1102
01:13:06,890 --> 01:13:15,820
ambapo kama kitu fulani ni alitangaza kwa ajili ya kitanzi, ni kwenda kukaa katika kwamba kwa kitanzi.

1103
01:13:15,820 --> 01:13:18,790
kitu sisi kweli huduma kuhusu kutumia JavaScript kwa ni kufanyia kurasa za mtandao, sawa?

1104
01:13:18,790 --> 01:13:21,800
I mean, hiyo ndiyo sababu sisi ni kufanya hivyo.

1105
01:13:21,800 --> 01:13:23,840
>> Kwa kufanya hivyo, sisi kutumia kitu kinachoitwa DOM.

1106
01:13:23,840 --> 01:13:25,850
Document Object Model.

1107
01:13:25,850 --> 01:13:29,430
Kimsingi, kile yake ni inachukua HTML yako yote

1108
01:13:29,430 --> 01:13:34,110
na mifano ni nje ndani ya rundo la vitu kwamba ni kuwekwa ndani ya kila mmoja.

1109
01:13:34,110 --> 01:13:37,080
Unaweza kuanza nje kwa kitu kama hiki.

1110
01:13:37,080 --> 01:13:44,770
Wewe, juu ya haki kwa ajili yangu, rundo la code huko nje kwamba ni aina ya -

1111
01:13:44,770 --> 01:13:46,640
Unaweza kudhani kwamba d kuwa vigumu sana kuendesha,

1112
01:13:46,640 --> 01:13:48,700
kwa sababu wewe d parsing kupitia kundi la Nakala

1113
01:13:48,700 --> 01:13:52,080
na kuwa na kipande mbali mambo. Na nini kama haikuwa kwa usahihi mpangilio?

1114
01:13:52,080 --> 01:13:54,880
Mambo mabaya ingeweza kutokea.

1115
01:13:54,880 --> 01:13:58,140
Hivyo JavaScript inachukua huduma ya hii kwa ajili yenu, na kupata muundo nzuri data,

1116
01:13:58,140 --> 01:14:01,390
kama moja upande wangu wa kushoto, ambapo wewe tu hati,

1117
01:14:01,390 --> 01:14:03,530
na ndani ya kwamba una kitu kinachoitwa HTML,

1118
01:14:03,530 --> 01:14:05,600
na ndani ya kwamba una kichwa na mwili,

1119
01:14:05,600 --> 01:14:08,420
na ndani ya kichwa kwamba una cheo, na kadhalika, na kadhalika, nakadhalika.

1120
01:14:08,420 --> 01:14:11,810
Hii simplifies kufanyia ukurasa mtandao ili tu,

1121
01:14:11,810 --> 01:14:14,190
oh, mimi nataka tu kuzungumza na hii kitu.

1122
01:14:14,190 --> 01:14:21,340
Aina ya njia sawa na ungependa kuzungumza na mwingine kitu umefanya mwenyewe.

1123
01:14:21,340 --> 01:14:25,980
Kama nilivyosema, DOM yote ni katika hati kitu.

1124
01:14:25,980 --> 01:14:29,290
Ama ni tu sehemu moja na kisha unaweza kwenda ndani yake kupata mambo,

1125
01:14:29,290 --> 01:14:33,880
na unaweza kufanya hivyo - hii ni style ya zamani ya kufanya hivyo, huko,

1126
01:14:33,880 --> 01:14:38,130
ambapo unaweza kufanya document.getElementById, na kisha jina,

1127
01:14:38,130 --> 01:14:42,420
na kama pengine unaweza kuwaambia, hii anapata unwieldy sana baada ya muda.

1128
01:14:42,420 --> 01:14:44,480
Hivyo pengine hawataki kufanya hivyo. Hiyo ndiyo sababu tuna

1129
01:14:44,480 --> 01:14:48,760
Jambo la pili tunakwenda majadiliano juu ya baada ya hii.

1130
01:14:48,760 --> 01:14:52,510
Jambo muhimu hapa ni kwamba, kila haki, una mambo haya yote, sawa?

1131
01:14:52,510 --> 01:14:56,400
Hivyo labda naweza kubadili alama ya kitu wakati ukurasa mizigo.

1132
01:14:56,400 --> 01:14:58,380
Basi ni nini? Nini kama user wangu Clicks kitu?

1133
01:14:58,380 --> 01:15:00,540
Mimi nataka kufanya jambo la kuvutia wakati wao bonyeza kitu.

1134
01:15:00,540 --> 01:15:02,600
Hiyo ndiyo sababu tuna matukio.

1135
01:15:02,600 --> 01:15:05,330
Unaweza, kimsingi, kupata hiki yoyote katika DOM yako,

1136
01:15:05,330 --> 01:15:08,560
na kisha kusema, hey. Wakati hii mizigo au mtu Clicks yake,

1137
01:15:08,560 --> 01:15:11,410
au wakati wao panya juu yake, kufanya kitu kwa hayo.

1138
01:15:11,410 --> 01:15:15,330
Na nini ni, una kazi ambayo kushughulikia suala hili kwa ajili yenu.

1139
01:15:15,330 --> 01:15:17,980
Kazi hizi ni tukio la handlers.

1140
01:15:17,980 --> 01:15:20,440
Nini they're - ni njia tu dhana ya kusema,

1141
01:15:20,440 --> 01:15:23,500
kazi hii ni kunyongwa tu wakati tukio hili hufanyika.

1142
01:15:23,500 --> 01:15:28,070
Hivyo Hushughulikia tukio hilo kuwa hutokea.

1143
01:15:28,070 --> 01:15:30,810
Hii ni jinsi gani kuweka tukio handler.

1144
01:15:30,810 --> 01:15:34,750
Mimi na baadhi ya kifungo, na wakati bonyeza yake, unatokea.

1145
01:15:34,750 --> 01:15:40,560
Hivyo si bonyeza button.

1146
01:15:40,560 --> 01:15:42,910
Hii ni njia moja ya inakaribia yake, sawa?

1147
01:15:42,910 --> 01:15:46,430
Una tag kifungo, na juu ya click una kamba kwamba anasema,

1148
01:15:46,430 --> 01:15:50,460
oh, kwa njia, mimi kufanya jambo hili kulipuka kwa ajili yangu.

1149
01:15:50,460 --> 01:15:53,990
Vinginevyo, ni tu kama kifungo mara kwa mara tu kufanywa.

1150
01:15:53,990 --> 01:15:56,550
Unaweza pia kufanya hii kwa njia nyingine,

1151
01:15:56,550 --> 01:16:02,770
kwa grabbing DOM hiki, lakini tutaweza kuokoa kwamba baada ya sisi majadiliano juu ya jQuery.

1152
01:16:02,770 --> 01:16:07,580
>> JQuery: Ni maktaba ambayo ni msalaba-browser.

1153
01:16:07,580 --> 01:16:09,580
Unaweza kutumia katika pretty kiasi chochote.

1154
01:16:09,580 --> 01:16:12,090
Na tu inakupa mengi ya zana kufanya kazi pamoja.

1155
01:16:12,090 --> 01:16:15,850
Kwa sababu JavaScript, wakati nguvu, hana zana zote unahitaji

1156
01:16:15,850 --> 01:16:20,550
nje ya boksi kwa kweli kukabiliana na programu mtandao unaweza kutaka kufanya.

1157
01:16:20,550 --> 01:16:24,650
Hivyo simplifies mambo mengi, anatoa mengi ya kazi

1158
01:16:24,650 --> 01:16:28,760
nje ya boksi kuwa wewe kawaida na kuandika mwenyewe, tena na tena na tena.

1159
01:16:28,760 --> 01:16:31,600
Na tu hufanya mambo rahisi sana.

1160
01:16:31,600 --> 01:16:35,780
Unaweza pia kuwa na selectors, ambayo basi wewe kuchukua wale mambo yote

1161
01:16:35,780 --> 01:16:42,800
kutoka DOM yako mengi zaidi tu, badala ya kuwa na matumizi ya simu hizi kazi kwa muda mrefu sana.

1162
01:16:42,800 --> 01:16:46,630
Zaidi juu ya selectors haya. Wewe, hadi pale una, hebu sema

1163
01:16:46,630 --> 01:16:49,800
Nataka kupata hiki na ID "mwamba."

1164
01:16:49,800 --> 01:16:56,450
Naam, katika jQuery, ni tu $ na kisha kamba ambayo ina chupa, na kisha "mwamba."

1165
01:16:56,450 --> 01:17:01,960
Ni rahisi sana na mengi zaidi kuliko jadi JavaScript njia ya kukabiliana na tatizo hili.

1166
01:17:01,960 --> 01:17:06,120
Na una mambo sawa kwa ajili ya madarasa na aina hiki.

1167
01:17:06,120 --> 01:17:08,140
jQuery ni - moja ya makala ya baridi ni wewe unaweza aina ya kubana

1168
01:17:08,140 --> 01:17:14,350
chini maswali yako juu ya DOM yako sana, kwa haraka sana.

1169
01:17:14,350 --> 01:17:18,980
Sasa tuko nyuma kwa tukio utunzaji, na hii ni jinsi gani ya kushughulikia tukio moja katika jQuery.

1170
01:17:18,980 --> 01:17:23,090
Hivyo nini tunakwenda hapa ni sisi ni kusema, haki ya wote. Nina tag script, sawa?

1171
01:17:23,090 --> 01:17:25,400
Hivyo nina inline hii JavaScript.

1172
01:17:25,400 --> 01:17:27,750
Nini tunakwenda kufanya ni tunakwenda kusema, haki ya wote.

1173
01:17:27,750 --> 01:17:30,860
Wakati hati ni tayari, ambayo ina maana hati imekuwa kubeba,

1174
01:17:30,860 --> 01:17:34,660
sisi ni kwenda katika kazi hiyo, na sisi ni kwenda kusema, haki ya wote,

1175
01:17:34,660 --> 01:17:37,060
kazi hii ni kweli kufanya kitu kingine.

1176
01:17:37,060 --> 01:17:42,320
Ni kimsingi akisema, sawa, mimi kupata hiki na ID "MyID."

1177
01:17:42,320 --> 01:17:47,960
Na kisha kutoa hii kazi handler kwamba executes wakati bonyeza yake.

1178
01:17:47,960 --> 01:17:49,820
Kimsingi nini hii haina ni, inasema, sawa.

1179
01:17:49,820 --> 01:17:52,630
ukurasa ni kubeba, hivyo mimi nina kwenda katika, kupata kipengele hiki,

1180
01:17:52,630 --> 01:17:56,420
kuwapa hii handler tukio hilo, na kimsingi unaweka juu ya ukurasa wako kwa ajili yenu.

1181
01:17:56,420 --> 01:18:00,520
Na hii ni jinsi gani kufikiria juu ya tukio hilo kuchukua.

1182
01:18:00,520 --> 01:18:06,310
Wewe tu nataka kufikiri kuhusu, sawa, wakati kitu hutokea, je, nataka kutokea?

1183
01:18:06,310 --> 01:18:10,520
Hawataki kufikiri juu ya, okay, mimi haja ya kuhakikisha mazungumzo jambo hili kwa jambo hili,

1184
01:18:10,520 --> 01:18:14,660
jambo hili blah blah blah, kwa sababu wewe tu unataka kuzungumza kitu katika suala la matukio.

1185
01:18:14,660 --> 01:18:17,650
Wakati hii itatendeka, hii hutokea. Wakati hii itatendeka, ambayo hufanyika.

1186
01:18:17,650 --> 01:18:20,240
Na kama mambo kusababisha mambo mengine, kwamba ni kubwa.

1187
01:18:20,240 --> 01:18:22,150
Lakini hawataki kujaribu na kufanya ngumu code

1188
01:18:22,150 --> 01:18:24,130
ambapo wewe ni kuchochea mambo mbalimbali wakati huo huo,

1189
01:18:24,130 --> 01:18:28,860
kwa sababu wewe ni tu kwenda kutoa mwenyewe maumivu ya kichwa.

1190
01:18:28,860 --> 01:18:32,340
>> Sawa. Sasa tunaweza kupata ukurasa yetu ya kushughulikia matukio,

1191
01:18:32,340 --> 01:18:35,640
lakini hebu sema user yangu Clicks kifungo.

1192
01:18:35,640 --> 01:18:38,040
Nini kama mimi unataka kutuma ombi kwamba nyuma ya server,

1193
01:18:38,040 --> 01:18:41,100
lakini mimi sitaki upya ukurasa, kwa sababu ya kuwa na upya ukurasa mpya

1194
01:18:41,100 --> 01:18:44,390
kila wakati anapata aina ya nyeti, na kwa nini mimi haja

1195
01:18:44,390 --> 01:18:47,430
kubomoa header tena, na footer tena,

1196
01:18:47,430 --> 01:18:49,670
na mambo yote ya ukurasa tena

1197
01:18:49,670 --> 01:18:53,180
tu mahitaji salamu au wakati?

1198
01:18:53,180 --> 01:18:55,290
Hivyo ndiyo sababu tuna kitu kama Ajax.

1199
01:18:55,290 --> 01:18:59,150
Nini tunaweza kufanya hapa na Ajax ni tunaweza kusema, haki ya wote,

1200
01:18:59,150 --> 01:19:01,290
Nataka kupeleka baadhi data kwa server,

1201
01:19:01,290 --> 01:19:04,010
na mimi nataka kupata majibu nyuma hivyo siwezi update ukurasa wangu,

1202
01:19:04,010 --> 01:19:12,120
au labda tu kufanya baadhi ya hesabu algorithmic kwamba siyo lazima kuonyesha kitu chochote kwa mtumiaji.

1203
01:19:12,120 --> 01:19:15,500
Je, unahitaji kufanya hili? Vizuri, unahitaji URL unahitaji kuzungumza.

1204
01:19:15,500 --> 01:19:18,650
Server yako huwezi magically kusikiliza kutoka popote.

1205
01:19:18,650 --> 01:19:21,960
Unahitaji kuwa na mahali maalum wewe ni kutuma data hii.

1206
01:19:21,960 --> 01:19:26,240
Na wewe pia haja ya baadhi ya data kutuma, au labda ni dataless swala.

1207
01:19:26,240 --> 01:19:31,380
Unataka tu Ping nyuma server na kusema, hey, mimi niko hai, au kitu kama hicho.

1208
01:19:31,380 --> 01:19:35,150
Na kisha unataka kazi ambayo kimsingi Hushughulikia na mafanikio.

1209
01:19:35,150 --> 01:19:38,250
Hebu sema wewe kupata nyuma baadhi ya taarifa kutoka kompyuta yako,

1210
01:19:38,250 --> 01:19:42,960
na unataka kubadili jina la mtumiaji juu ya ukurasa yao.

1211
01:19:42,960 --> 01:19:44,930
Hivyo ungependa kupata habari nyuma,

1212
01:19:44,930 --> 01:19:48,860
na ungependa kushinikiza kwamba screen.

1213
01:19:48,860 --> 01:19:51,170
Nini kinatokea ni kwamba, wakati ukurasa ni tayari,

1214
01:19:51,170 --> 01:19:56,500
kujenga juu ya click kazi kwa ajili ya kifungo hii inayoitwa greeter.

1215
01:19:56,500 --> 01:19:58,810
Nini hii haina kisha ni, wakati kwamba kifungo ni kusukuma,

1216
01:19:58,810 --> 01:20:03,700
kuongea na greetings.php, unaweza kufanya ombi POST,

1217
01:20:03,700 --> 01:20:07,290
na kusema, hey, mimi kupata kitu kutoka ukurasa wako.

1218
01:20:07,290 --> 01:20:09,890
Sisi si kweli haja ya kueleza kwamba, lakini greetings.php,

1219
01:20:09,890 --> 01:20:12,480
hebu sema tu, inatoa nyuma "hello dunia."

1220
01:20:12,480 --> 01:20:15,650
Ili tuweze kupata nyuma hii "hello dunia," na mafanikio ya mpango huu,

1221
01:20:15,650 --> 01:20:20,730
kuchukua kitu kitaenda vibaya, kisha sisi tu kwenda hii mahali lengo

1222
01:20:20,730 --> 01:20:25,720
kwamba sisi maalum na sisi tu fimbo majibu huko.

1223
01:20:25,720 --> 01:20:31,560
Na hii ni njia rahisi sana ya kuanzisha Ajax swala.

1224
01:20:31,560 --> 01:20:34,340
>> Haraka sana, Rob aina ya zilizotajwa hii tayari,

1225
01:20:34,340 --> 01:20:37,170
mambo yanaweza kwenda vibaya, mambo mabaya yanaweza kutokea,

1226
01:20:37,170 --> 01:20:42,660
hivyo unataka familiarize mwenyewe na kanuni hizi HTTP majibu.

1227
01:20:42,660 --> 01:20:46,030
Hawa ni nini ni haki, kama, 200, kila kitu akaenda sawa.

1228
01:20:46,030 --> 01:20:48,670
Kitu kingine, mambo mabaya kilichotokea.

1229
01:20:48,670 --> 01:20:50,790
Ni kwa ujumla jambo unataka kukumbuka.

1230
01:20:50,790 --> 01:20:53,440
Lakini ni nzuri kujua yote haya.

1231
01:20:53,440 --> 01:20:55,970
Na hatimaye, mara moja tumeenda kwa njia zote za kwamba,

1232
01:20:55,970 --> 01:20:58,680
sisi haja ya kuzungumza kwa haraka sana juu ya mpango,

1233
01:20:58,680 --> 01:21:00,620
na kisha tunaweza basi wewe wote kuondoka.

1234
01:21:00,620 --> 01:21:03,410
Design. Mambo unataka kukumbuka.

1235
01:21:03,410 --> 01:21:06,950
Jiulize maswali haya: Nani utakuwa kutumia hii?

1236
01:21:06,950 --> 01:21:09,580
Nini wao kutumia kwa? Je, watumiaji yangu huduma ya juu?

1237
01:21:09,580 --> 01:21:11,750
Je, si wao huduma ya juu?

1238
01:21:11,750 --> 01:21:14,500
Wewe tu hawataki kufanya programu na basi ni tu kukua

1239
01:21:14,500 --> 01:21:18,270
na kuwa hii kubwa, kila mwingi kitu kwamba huwezi hata kumaliza.

1240
01:21:18,270 --> 01:21:23,900
Unataka kuwa na malengo za kipekee na mipango na mambo unataka kushughulikia.

1241
01:21:23,900 --> 01:21:29,000
Kufanya hivyo effortless. Yote hii anasema, kimsingi,

1242
01:21:29,000 --> 01:21:34,950
kufanya hivyo ni rahisi kwa mtumiaji kuitumia, wala kufanya hivyo Blob kubwa ya maandishi kama slide hii ni, kwa kweli.

1243
01:21:34,950 --> 01:21:38,020
Wewe unataka tu ni kuwa kitu ambapo ni rahisi sana kwa mtu kwenda katika

1244
01:21:38,020 --> 01:21:40,800
na kufanya nini wanataka kufanya.

1245
01:21:40,800 --> 01:21:42,920
Hawataki wao kuwa na navigate 5 kurasa

1246
01:21:42,920 --> 01:21:45,460
kupata kazi yako mkuu wa tovuti yako.

1247
01:21:45,460 --> 01:21:49,290
Kama Google alikuwa kurasa 5 kabla unaweza hata kutafuta kitu,

1248
01:21:49,290 --> 01:21:53,080
hakuna mtu matumizi yake.

1249
01:21:53,080 --> 01:21:55,890
Na mwisho, karatasi mfano, vikundi.

1250
01:21:55,890 --> 01:21:59,220
Na design nzuri na mazoea ya kupima.

1251
01:21:59,220 --> 01:22:00,730
Kwa sababu tu unafikiri kazi kwa ajili yenu,

1252
01:22:00,730 --> 01:22:04,860
haina maana mtu mwingine anadhani ni kazi.

1253
01:22:04,860 --> 01:22:14,490
Lakini yeah, hiyo ni yake.

1254
01:22:14,490 --> 01:22:17,490
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