C Tutorial/ctype.h/isxdigit
isxdigit
Item Value Header file ctype.h Declaration int isxdigit(int ch); Return returns nonzero if ch is a hexadecimal digit; otherwise zero is returned.
A hexadecimal digit will be in one of these ranges: A-F, a-f, or 0-9.
#include <ctype.h>
#include <stdio.h>
int main(void)
{
char ch;
for(;;) {
ch = getchar();
if(ch == "."){
break;
}
if(isxdigit(ch))(){
printf("%c is hexadecimal digit\n", ch);
}
}
return 0;
}