Thread: Character function not returning

Hello,
I'm compiling with Dev-c++ 4.01. This routine accepts
six alphanumeric characters, e.g. A1B2C3, and is
part of a mailing list program.

The program compiles without errors. When run it
seems to skip over the character functions (no input),
and prints the error handling statement:"The ZIPcode
must be alphanumeric only."

What am I doing wrong? Am I omitting something,
or is the design faulty?

This is what I'm able to do.

Thank you.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>

/*Prototype*/

char err_msg(char msg[]);
char getzip(char zipcode[]);
int main();


char err_msg(char msg[])  {
printf("\n\n%s\n", msg);
fflush(stdout);
return;
}
char getzip(char zipcode[])
{
      int ctr;
      for(ctr = 0; ctr < 6; ctr++)
     {
          zipcode [ctr] = toupper(zipcode [ctr]);
               if(! isalpha(zipcode [ctr]))
               {
                     if(! isdigit(zipcode[ctr]))
                        {continue;}
                   else
                         {
                              err_msg("The ZIPcode must be alphanumeric only");
                             break;
                         }
                 }
         }
 }
int main()
{
     int ch;
     char zipcode[7];          /*Extra null character.*/

     do
         {
              ch = 0;

              printf("Enter ZIPcode");
              fgets(zipcode, 7, stdin);
              while(getchar() != '\n');
               ch = 1;
         }
               while(ch);
               system("PAUSE");
               return;
    }

Code:

if(! isdigit(zipcode[ctr]))

Are you sure the above line is correct. As it stands now, if your zipcode contains numbers, it will go to the error message.