老外写的程序也不是那么完美啊：在C#中实现类似VBScript中Right()函数

http://www.csharphelp.com/archives4/archive616.html 上是这样写的：
        public static string Right(string param, int length)
        {
            //start at the index based on the lenght of the sting minus
            //the specified lenght and assign it a variable
            string result = param.Substring(param.Length - length, length);
            //return the result of the operation
            return result;
        }

假定字符串的长度是5位，而我们不知道这个字符串的长度，为了避免截断字符串，给 length 传了个6，这时就抛出 ArgumentOutOfRangeException 异常了。


我的代码如下：
public static string RightString(string sourceString, int length)
{
    return (sourceString.Length > length) ? sourceString.Substring(sourceString.Length - length) : sourceString;
}