C库函数 islower()

#include <stdio.h>

#include <ctype.h>



int main () {

   int var1 = 'Q';

   int var2 = 'q';

   int var3 = '3';



   if( islower(var1) ) {

      printf("var1 = |%c| is lowercase character\n", var1 );

   } else {

      printf("var1 = |%c| is not lowercase character\n", var1 );

   }



   if( islower(var2) ) {

      printf("var2 = |%c| is lowercase character\n", var2 );

   } else {

      printf("var2 = |%c| is not lowercase character\n", var2 );

   }



   if( islower(var3) ) {

      printf("var3 = |%c| is lowercase character\n", var3 );

   } else {

      printf("var3 = |%c| is not lowercase character\n", var3 );

   }



   return(0);

}