Switch语句贯穿是我个人喜欢Switch vs. if/else if结构的主要原因之一。下面是一个例子:
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;
}
聪明的人畏缩不前，因为字符串[]应该在函数之外声明:好吧，它们是，这只是一个例子。
编译器失败，出现以下错误:
Control cannot fall through from one case label ('case 3:') to another
Control cannot fall through from one case label ('case 2:') to another
为什么?有没有什么方法能让这种行为不需要三个如果呢?
