C库函数 isdigit()

#include <stdio.h>

#include <ctype.h>



int main () {

   int var1 = 'h';

   int var2 = '2';



   if( isdigit(var1) ) {

      printf("var1 = |%c| is a digit\n", var1 );

   } else {

      printf("var1 = |%c| is not a digit\n", var1 );

   }



   if( isdigit(var2) ) {

      printf("var2 = |%c| is a digit\n", var2 );

   } else {

      printf("var2 = |%c| is not a digit\n", var2 );

   }



   return(0);

}