isdigit()

tests if character is a digit 

Function


SYNOPSIS

#include <ctype.h>

int isdigit(int c);


DESCRIPTION

The isdigit() function tests for any decimal-digit character.

The behavior of the isdigit() 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 isdigit() 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.


CONFORMANCE

ANSI/ISO 9899-1990.


MULTITHREAD SAFETY LEVEL

MT-Safe, with exceptions.

This function is MT-Safe as long as no thread calls setlocale() while this function is executing.


PORTING ISSUES

None.


AVAILABILITY

PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition


SEE ALSO

Functions:
isalnum(), isalpha(), isascii(), iscntrl(), isgraph(), islower(), isprint(), ispunct(), isspace(), isupper(), isxdigit(), setlocale()


PTC MKS Toolkit 9.6 patch 1 Documentation Build 5.