isalnum in c
#include <stdio.h>
#include <ctype.h>
int main()
{
char c;
int result;
c = '5';
result = isalnum(c);
printf("When %c is passed, return value is %d\n", c, result);
c = 'Q';
result = isalnum(c);
printf("When %c is passed, return value is %d\n", c, result);
c = 'l';
result = isalnum(c);
printf("When %c is passed, return value is %d\n", c, result);
c = '+';
result = isalnum(c);
printf("When %c is passed, return value is %d\n", c, result);
return 0;
}