C Primer Plus, Fourth Edition

Programming Exercises

1. Rewrite the program in Listing 12.4 so that it does not use global variables.

2. Gasoline consumption commonly is computed in miles per gallon in the U.S. and in liters per 100 kilometers in Europe. What follows is part of a program that asks the user to choose a mode (metric or US), and then gathers data and computes fuel consumption:

   // pe12-x1.c
   #include <stdio.h>
   #include "pe12-2a.h"
   int main(void)
   {
     int mode;
   
     printf("Enter 0 for metric mode, 1 for US mode: ");
     scanf("%d", &mode);
     while (mode >= 0)
     {
        set_mode(mode);
        get_info();
        show_info();
        printf("Enter 0 for metric mode, 1 for US mode");
        printf(" (-1 to quit): ");
        scanf("%d", &mode);
     }
     printf("Done.\n");
     return 0;
   }
   

   Here is some sample output:

    Enter 0 for metric mode, ...