menu2.c

来自「c21Examples.rar」· C语言 代码 · 共 83 行

/* Demonstrates using an infinite loop and the switch */
/* statement to implement a menu system. */
#include <stdio.h>
#include <stdlib.h>

#define DELAY 150000

int menu(void);
void delay(void);

int main( void )
{
   int command = 0;
   command = menu();

   while (command != 5 )
   {
         /* Get user's selection and branch based on the input. */

         switch(command)
         {
            case 1:
                {
                  puts("\nExecuting task A.");
                  delay();
                  break;
                }
            case 2:
                {
                  puts("\nExecuting task B.");
                  delay();
                  break;
                }
            case 3:
                {
                  puts("\nExecuting task C.");
                  delay();
                  break;
                }
            case 4:
                {
                  puts("\nExecuting task D.");
                  delay();
                  break;
                }
            case 5:     /* Exit program. */
                {
                  puts("\nExiting program now...\n");
                }
            default:
                {
                  puts("\nInvalid choice, try again.");
                }
         }  /* End of switch */
         command = menu();
    }       /* End of while  */
    return 0;
}

/* Displays a menu and inputs user's selection. */
int menu(void)
{
    int reply;

    puts("\nEnter 1 for task A.");
    puts("Enter 2 for task B.");
    puts("Enter 3 for task C.");
    puts("Enter 4 for task D.");
    puts("Enter 5 to exit program.");

    scanf("%d", &reply);

    return reply;
}

void delay( void )
{
    long x;
    for( x = 0; x < DELAY; x++ )
        ;
}