Description
The isalnum() function tests for any character for which
int isalpha(int c) or
int isdigit(int c) is true.
The behavior of the isalnum() function is affected by the current locale. To modify the behavior, change the LC_CTYPE category in setlocale(), that is, setlocale(LC_CTYPE, newlocale). In the C locale or in a locale where character type information is not defined, characters are classified according to the rules of the U.S. ASCII 7-bit coded character set.
Parameters
- c
Is an integer whose value is representable as an unsigned char or the value of the macro EOF.
Return Values
The isalnum() function returns non-zero for true and zero for false. If the parameter is not in the domain of the function, the return result is undefined.