C#小知识点记录

1     public static string CompareExchange(
2     ref string location1,
3     string value,
4     string comparand
5 )

1     static string CompareExchange(ref string location1, string value, string comparand)
2         {
3             if(location1==comparand)
4             {
5                 location1 = value;
6             }
7             return value;
8         }