Solution for Exercise 16-10

ex1610

#include <stdio.h>

int main()
{
    enum { SUN, MON, TUE, WED, THU, FRI, SAT };
    int day;

    printf("Enter a weekday number, 0 - 6: ");
    scanf("%d",&day);

    if( day < 0 || day > 6 )
    {
        puts("Invalid input");
    }
    else
    {
        switch(day)
        {
            case SUN:
                puts("Sunday");
                break;
            case MON:
                puts("Monday");
                break;
            case TUE:
                puts("Tuesday");
                break;
            case WED:
                puts("Wednesday");
                break;
            case THU:
                puts("Thursday");
                break;
            case FRI:
                puts("Friday");
                break;
            case SAT:
                puts("Saturday");
        };
    }
    return(0);
}

Output

Enter a weekday number:, 0 - 6: 4
Thursday

Notes

* I used all caps for my enumerated constants, declared at Line 5. You could use lower case and you could have even specified the full day name.

* What the enumerated constants do here is make the case statements more readable.

* A final break in the case SAT: block isn't required because the if test (Line 11) eliminates any other possibilities. Similarly, a default part of the structure isn't necessary.

Exercise ex1701 →