小编典典

C#中的switch语句失败?

c#

switch语句的下通是为爱我个人的一个重要原因switchif/else if结构。这里有一个示例:

static string NumberToWords(int number)
{
    string[] numbers = new string[] 
        { "", "one", "two", "three", "four", "five", 
          "six", "seven", "eight", "nine" };
    string[] tens = new string[] 
        { "", "", "twenty", "thirty", "forty", "fifty", 
          "sixty", "seventy", "eighty", "ninety" };
    string[] teens = new string[]
        { "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen",
          "sixteen", "seventeen", "eighteen", "nineteen" };

    string ans = "";
    switch (number.ToString().Length)
    {
        case 3:
            ans += string.Format("{0} hundred and ", numbers[number / 100]);
        case 2:
            int t = (number / 10) % 10;
            if (t == 1)
            {
                ans += teens[number % 10];
                break;
            }
            else if (t > 1)
                ans += string.Format("{0}-", tens[t]);
        case 1:
            int o = number % 10;
            ans += numbers[o];

            break;
        default:
            throw new ArgumentException("number");
    }
    return ans;
}

聪明人之所以屈服,是因为string[]s应该在函数外部声明:好的,这只是一个例子。

编译器失败,并出现以下错误:

控件不能从一个案例标签(“案例3:”)落入另一个案例标签
控件不能从一个案例标签(“案例2:”)落入另一个案例标签

为什么?还有没有三秒就可以得到这种行为的任何方法if吗?


阅读 275

收藏
2020-05-19

共1个答案

小编典典

(复制/粘贴我在其他地方提供答案

通过下降switch- caseS可通过不具有代码在一个来实现case(见case 0),或者使用特殊的goto case(见case 1)或goto default(见case 2)形式:

switch (/*...*/) {
    case 0: // shares the exact same code as case 1
    case 1:
        // do something
        goto case 2;
    case 2:
        // do something else
        goto default;
    default:
        // do something entirely different
        break;
}
2020-05-19