很菜，题：编写一个函数使形如“Good afteroon sir”变成“sir afternoon Good”

很菜，求一个题：编写一个函数使形如“Good afteroon sir”变成“sir afternoon Good”
编写一个函数使形如“Good   afteroon   sir”变成“sir   afternoon   Good”
谢谢！~~

[解决办法]
string str = "Good afteroon sir ";
string[] astr = str.Split( ' ');
Array.Reverse(astr);
str = string.Join( " ", astr);