1 00:00:00,000 --> 00:00:00,310 2 00:00:00,310 --> 00:00:01,750 >> DAVID Malan: Se pou nou kounye a kònen lide ou. 3 00:00:01,750 --> 00:00:06,500 Li sanble nan mond reyèl la 1 divize pa 10 se vre 1/10, oswa 0.1. 4 00:00:06,500 --> 00:00:10,370 Men, nan òdinatè ke se sèlman gen yon fini kantite Bits ak ki 5 00:00:10,370 --> 00:00:14,290 reprezante chif, ou pa ka toujou reprezante chif tankou 1/10 ak 6 00:00:14,290 --> 00:00:15,500 pafè presizyon. 7 00:00:15,500 --> 00:00:18,640 Nan lòt mo, òdinatè pafwa gen fè apèl jijman epi yo pa 8 00:00:18,640 --> 00:00:22,740 nesesèman reprezante ki kantite ou vle kòm jisteman jan ou gen entansyon. 9 00:00:22,740 --> 00:00:27,020 >> Pou egzanp, ann sipoze m 'ale tounen nan pwogram sa a ak chanje 0.1 a, 10 00:00:27,020 --> 00:00:32,073 oh, 0,28, kidonk ki endike ke Mwen ta renmen printf printf 11 00:00:32,073 --> 00:00:34,350 28 kote nan presizyon. 12 00:00:34,350 --> 00:00:39,330 Se pou nou kounye a sove epi pou konpile pwogram nan, tan sa a ak fè floats2. 13 00:00:39,330 --> 00:00:41,910 Kouri l 'ak dot floats2 koupe. 14 00:00:41,910 --> 00:00:49,980 Epi, mwen renmen anpil Bondye, fwa sa a mwen wè pa 0.1, men 0.10000000, ki se trè 15 00:00:49,980 --> 00:00:51,070 bon twò lwen. 16 00:00:51,070 --> 00:00:57,830 Men, lè sa a, 14901161193847656250. 17 00:00:57,830 --> 00:00:58,880 >> Oke, sa k ap pase sou? 18 00:00:58,880 --> 00:01:02,280 Oke, li sanble ke yon flote se anjeneral yo estoke andedan nan yon òdinatè 19 00:01:02,280 --> 00:01:03,500 ak 32 miyèt moso. 20 00:01:03,500 --> 00:01:07,340 32 se evidamman yon nimewo fini, ki implique ke ou ka sèlman reprezante 21 00:01:07,340 --> 00:01:11,050 ak 32 Bits yon nimewo fini nan k ap flote valè pwen. 22 00:01:11,050 --> 00:01:14,980 Malerezman, sa vle di nan òdinatè pa ka reprezante tout sa ki posib 23 00:01:14,980 --> 00:01:18,110 nimewo k ap flote pwen, oswa chif reyèl, ki egziste nan mond lan, 24 00:01:18,110 --> 00:01:19,980 paske li sèlman gen anpil miyèt moso. 25 00:01:19,980 --> 00:01:23,940 >> Se konsa, sa ki òdinatè a nan aparamman fè l 'nan ka sa a se reprezante 1/10 a 26 00:01:23,940 --> 00:01:26,880 k ap flote ki pi pre posib valè pwen ke li kapab. 27 00:01:26,880 --> 00:01:31,050 Men, si nou gade, kòm nou gen isit la, nan 28 kote desimal, nou kòmanse wè ke 28 00:01:31,050 --> 00:01:31,970 enpresizyon. 29 00:01:31,970 --> 00:01:34,480 Se konsa, sa a se yon pwoblèm ak pa gen solisyon pafè. 30 00:01:34,480 --> 00:01:38,060 Nou ka sèvi ak yon doub olye de yon flote, ki gen tandans yo sèvi ak 64 Bits kòm 31 00:01:38,060 --> 00:01:39,410 yo te opoze ak 32. 32 00:01:39,410 --> 00:01:42,290 Men, nan kou, 64 se tou fini, Se konsa, pwoblèm nan ap 33 00:01:42,290 --> 00:01:43,630 rete menm ak double. 34 00:01:43,630 --> 00:01:46,323