The function prototype of isxdigit() is:
int isxdigit( int arg );
It is defined in the <ctype.h> header file.
isxdigit() Parameters
The isxdigit() function takes a single character as a parameter.
Note: In C programming, characters are treated as int values internally.
C isxdigit() Return Value
If the argument passed to isxdigit() is
- a hexadecimal character,
isxdigit()returns a non-zero integer. - a non-hexadecimal character,
isxdigit()returns 0.
Example 1: C isxdigit() function
#include <ctype.h>#include <stdio.h>int main() { char c = '5'; int result; // hexadecimal character is passed result = isxdigit(c); // result is non-zero printf("Result when %c is passed to isxdigit(): %d", c, isxdigit(c)); c = 'M'; // non-hexadecimal character is passed result = isxdigit(c); // result is 0 printf("\nResult when %c is passed to isxdigit(): %d", c, isxdigit(c)); return 0;}Output
Result when 5 is passed to isxdigit(): 128Result when M is passed to isxdigit(): 0
Example 2: Program to Check Hexadecimal Character
#include <ctype.h>#include <stdio.h>int main() { char c = '5'; printf("Enter a character: "); c = getchar(); if (isxdigit(c) != 0) { printf("%c is a hexadecimal character.", c); } else { printf("%c is not a hexadecimal character.", c); } return 0;}Output
Enter a character: ff is a hexadecimal character.
