studying before implementing some functions of <ctype.h> Lib.
#include <ctype.h>
- isalpha()
- isdigit()
- isalnum()
- isascii()
- isprint()
- toupper()
- tolower()
int isalpha(int c);
tests for any character for which isupper or islower is true.
return values
: 0 - if the character tests false.
non-zero - if the character tests true.
int isdigit(int c);
tests for a decimal digit character.
- diffence with isnumber()
-isdigit() only recognizes decimal number. but isnumber() may recognizes additional characters depending on the current locale setting.
return values
: 0 - if the character tests false.
non-zero - if the character tests true.
int isalnum(int c);
tests for any character for which isalpha or isdigit is true.
return values
: 0- if the character tests false.
non-zero if the character tests true.
int isascii(int c);
tests for an ASCII character, which is any character between 0 and octal 0177 inclusive.
return values
: 0- if the character tests false.
non-zero if the character tests true.
int isprint(int c);
tests for any printing character, including space(ascii num 32).
return values
: 0- if the character tests false.
non-zero if the character tests true.
int toupper(int c);
converts a lower-case letter to the corresponding upper-case letter.
The argument must be representable as an unsigned char or the value of EOF.
return values
: the corresponding upper-case letter - if there is one and If the argument is a lower-case letter.
unchanged value - otherwise.
