Thread: user menu

what is the best way to have a menu and
ask for input and check for it.
this is what i have so far, its not finished
but i feel im not doing it right

Code:

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

#define MAXCUST 12

struct airline {
       unsigned int seat;
       char customer[MAXCUST];

};

char showmenu ( void );


int main(int argc, char *argv[])
{
    struct airline seat[BUFSIZ];
    char choice;
    
while ( ( choice = showmenu() )!= 'f' );
    {
        switch ( choice )
        {
          case 'a' : printf(" you hit a");
               break;
          
          case 'b' : printf(" you hit b");
               break;
          
          }
               
  system("PAUSE");	
  return 0;
}
}

char showmenu ( void )
{
  char ans;
  printf(" ********** Welcome to Swift Lines Airlines ************\n");
  printf("\n ********** To Choose A Function, Enter its Letter Label:\n");
  printf("\na ) Show Number of seats\n");
  printf("b ) Show List of seats\n");
  printf("c ) Show alphabetical list of seats\n");
  printf("d ) Assign a Customer to a seat assignment\n");
  printf("e ) Delete a seat assignment\n");
  printf("f ) Quit\n");
  
  ans = getchar();
  ans = tolower( ans );
  
  while ( strchr ( "abcdef" , ans ) == NULL )
  {
        puts( " please pick A - F :\n");
        ans = tolower( getchar() );
        }
   return ans;
}

output:

Code:

 ********** Welcome to Swift Lines Airlines ************

 ********** To Choose A Function, Enter its Letter Label:

a ) Show Number of seats
b ) Show List of seats
c ) Show alphabetical list of seats
d ) Assign a Customer to a seat assignment
e ) Delete a seat assignment
f ) Quit
a
 ********** Welcome to Swift Lines Airlines ************

 ********** To Choose A Function, Enter its Letter Label:

a ) Show Number of seats
b ) Show List of seats
c ) Show alphabetical list of seats
d ) Assign a Customer to a seat assignment
e ) Delete a seat assignment
f ) Quit
 please pick A - F :

why is it doing this?
thanks

In C a line of code is terminated with the semi-colon. In this line of code, you tell the program to call showmenu(), over and over, until the choice is 'f'.

Code:

while ( ( choice = showmenu() )!= 'f' );  /* <--note the semi-colon here */
    {
        switch ( choice )
        {
          case 'a' : printf(" you hit a");
               break;
          
          case 'b' : printf(" you hit b");
               break;
          
          }

If you move the semi-colon, you'll get a completely different result.

What I do is call the menu() function, and everything loops back to that function:

Code:

menu();

Then in menu(), I use a while(1) loop, to keep everything looping back, and include a line like this:

while (1)  {
   /* get user's choice here */
   /*handle other choices, of course (probably in a switch statement), which includes this: */
   if (choice == 'q' || choice == 'Q")
      break;
};  /*note the semi-colon placement */

Hope that helps.

ahhhhh thanks i didnt even notice that!
it works now...
ok i will check out your way and see what works ok for me..
thx

why is it doing this?

doing what?

Code:

          }
  }
  system("PAUSE");	
  return 0;
}

edit: beat

Originally Posted by robwhit

doing what?

Code:

          }
  }
  system("PAUSE");	
  return 0;
}

edit: beat

what it was doing was
displaying the menu twice and even though i selected a choice it was reading i wasnt.. but its fixed due to the missplaced ;

as for the system pause it was placed there by devc++ and i havent removed it!
thx

It was inside the loop. I assume you wanted it to be the last thing to be run, and not make the loop break out prematurely. If I was wrong, then, you are right. Otherwise, see what happens if you enter a wrong value.

I also made my first post when I thought that there were no replys yet. Sorry if that was confusing.