C程序开发经典实例之4

题目：请输入星期几的第一个字母来判断一下是星期几，如果第一个字母一样，则继续判断第二个字母。

1.程序分析：用情况语句比较好，如果第一个字母一样，则判断用情况语句或if语句判断第二个字母。

2.程序源代码： void main()
{
    char letter;
    printf("please input the first letter of someday\n");
    while((letter = getch()) != ''Y'') /* 当所按字母为Y时才结束 */
    {
        switch (letter)
        {
        case ''S'':
            printf("please input second letter\n");
            if((letter = getch()) == ''a'')
                printf("saturday\n");
            else if ((letter = getch()) == ''u'')
                printf("sunday\n");
            else printf("data error\n");
                break;
        case ''F'': printf("friday\n");break;
        case ''M'': printf("monday\n");break;
        case ''T'':
            printf("please input second letter\n");
            if((letter = getch()) == ''u'')
                printf("tuesday\n");
            else if ((letter = getch()) == ''h'')
                printf("thursday\n");
            else printf("data error\n");
                break;
        case ''W'': printf("wednesday\n"); break;
        default: printf("data error\n");
        }
    }
}