ctype Header File

#include <ctype.h>

C library containg functions related to character operations.

Functions

Function A non-zero (true) value is returned if...
int isalpha( char ) c is a letter
int isupper( char ) c is an uppercase letter
int islower( char ) c is a lowercase letter
int isdigit( char ) c is a digit
int isalnum( char ) c is a letter or digit
int isxdigit( char) c is a hex digit
int isspace( char ) c is a whitespace character
int ispunct( char ) c is a punctuation character
int isprint( char ) c is a printable character
int isgraph( char) c printable, not space
int iscntrl( char ) c is a control character
int isascii( char ) c is an ASCII code

char toupper( char )

Returns the uppercase letter corresponding to the letter passed to the function. Note, the content of the parameter passed to the function is not modified.

char tolower( char )

Returns the lowercase letter corresponding to the letter passed to the function. Note, the content of the parameter passed to the function is not modified.