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>> DAVID MALAN: Let's now refine
this program a bit.

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Wouldn't it be nice if there were a
function called, say, islower that

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could return true or false
based on whether a given

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character is lowercase?

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Wouldn't it be even nicer if there were
a function called toupper that

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could convert a lowercase
letter to uppercase?

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>> Well, it turns out that both functions
exist, and they're declared in a file

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called ctype.h.

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So let's add that file to my includes.

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include ctype.h.

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And now let's utilize both of those
functions, replacing first my if

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condition as follows.

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if islower s bracket i, thereby
returning true or false if the ith

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character in s is a lower case letter.

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And let's now replace my arithmetic
expression here with simply toupper of

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s bracket i, thereby returning the
uppercase equivalent of the ith

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character in s if it's lower case.

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>> I'm going to leave my else block alone,
because if the letter is not

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lowercase, I still want to
print it out unchanged.

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And let's now compile this program.

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Make [? capitalize1. ?]

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Let's now run the program
with capitalize1.

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And let's now type a word like
hello in all lowercase.

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H-E-L-L-O, Enter, and it indeed
prints in all uppercase.

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>> Let's try one more scenario, though,
this time inputting my own name with

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the first letter, D, capitalized
already, just in case I messed

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something up in my own code with the
capitalization of that char.

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Enter, but no, DAVID in all caps
prints this time as expected.

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