Is there a function in C which checks whether a character is a character or integer, etc?

Question

I have a a homework, and my professor said some of the students figured out that they could check whether the characters they read in are specific ones using a function. He said it was in the string.h library, but I checked and I don't see it. Can anybody point me in the right direction?

score 5 · Accepted Answer · answered Feb 22 '12 at 21:55

5

Can anybody point me in the right direction?

Look into the standard header ctype.h.

Side note, most of them are usually implemented as macros, see Plauger.

answered Feb 22 '12 at 21:55

cnicutar

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Thanks! New to C so I am not sure about where to access all the libraries or what all of them even are. Appreciate the link. – Andy Feb 22 '12 at 22:06

score 1 · Answer 2 · edited Feb 22 '12 at 22:08

1

The function isalpha can help you out finding the rest of them.

char c;
scanf("%c", &c);
if (isalpha(c))
  printf("You entered a letter of some alphabet\n");

edited Feb 22 '12 at 22:08

jørgensen

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answered Feb 22 '12 at 21:57

Eregrith

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Thanks! I appreciate the added visual plus the link. – Andy Feb 22 '12 at 22:07
@jørgensen is `isalpha` localized? For example if you enter an ascii-extended character like é, is `isalpha('é')` true? (I don't even know if you can do `'é'` ... XD) – Eregrith Feb 23 '12 at 08:43

score 0 · Answer 3 · answered Feb 22 '12 at 21:55

0

Check isalpha and isdigit functions.

answered Feb 22 '12 at 21:55

ouah

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score 0 · Answer 4 · answered Feb 22 '12 at 21:58

0

Could be strspn.

size_t strspn(const char *s, const char *accept);

The strspn() function calculates the length of the initial segment of s which consists entirely of characters in accept.

answered Feb 22 '12 at 21:58

jweyrich

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Is there a function in C which checks whether a character is a character or integer, etc?

4 Answers4