C语言实例17：exit()函数

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

int main(int argc, char *argv[])
{
    int month;
    int day;

    printf("please input the month number:");
    scanf("%d", &month);

    switch(month)
    {
        case 1:
        case 3:
        case 5:
        case 7:
        case 8:
        case 10:
        case 12: day = 31;
        break;

        case 4:
        case 6:
        case 9:
        case 11: day = 30;
        break;

        case 2:day = 28;
        break;

        default: exit(0);
    }

    printf("1999.%d has %d days.\n", month, day);
    system("pause");
    return 0;
}