isdigit c documentation code example
Example: isdigit in c
#include <stdio.h>
#include <ctype.h>
int main()
{
char c;
c='0';
printf("Result when numeric character is passed: %d", isdigit(c));
c='+';
printf("\nResult when non-numeric character is passed: %d", isdigit(c));
return 0;
}