isxdigit

int isxdigit( int ch );

Checks if the given character is a hexadecimal numeric character (0123456789abcdefABCDEF) or is classified as a hexadecimal character.

The behavior is undefined if the value of ch is not representable as unsigned char and is not equal to EOF.

Parameters

Return value

Non-zero value if the character is an hexadecimal numeric character, zero otherwise.

Notes

isdigit and isxdigit are the only standard narrow character classification functions that are not affected by the currently installed C locale, although some implementations (e.g. Microsoft in 1252 codepage) may classify additional single-byte characters as digits.

Example

#include <stdio.h>
#include <ctype.h>
#include <limits.h>
 
int main(void)
{
    for (int ndx=0; ndx<=UCHAR_MAX; ndx++)
        if (isxdigit(ndx)) printf("%c", ndx);
    printf("\n");
}

0123456789ABCDEFabcdef

References

• C17 standard (ISO/IEC 9899:2018):
• 7.4.1.12 The isxdigit function (p: 147)
• C11 standard (ISO/IEC 9899:2011):
• 7.4.1.12 The isxdigit function (p: 203)
• C99 standard (ISO/IEC 9899:1999):
• 7.4.1.12 The isxdigit function (p: 184)
• C89/C90 standard (ISO/IEC 9899:1990):
• 4.3.1.11 The isxdigit function

See also