写程序结果题

[longwangjiayou]

程序运行结果为________
using System;
public class Test
{ public void change(string s)
{ s = s + "change1"; }
public void change(ref string s)
{ s = s + "change2"; }
public void change(string s1, out string s2)
{ s1 = s1 + "change3";
s2 = s1;
}
}
public class Exe8
{
static void Main()
{
string s1, s2;
s1 = "hello,";
Test t1 = new Test();
t1.change(s1);
Console.WriteLine("s1 after call to change1 is {0}", s1);
t1.change(ref s1);
Console.WriteLine("s1 after call to change2 is {0}", s1);
t1.change(s1, out s2);
Console.WriteLine("s1 after call to change3 is {0}", s1);
Console.WriteLine("s2 after call to change3 is {0}", s2);
Console.Read();
}
}
麻烦大家看下这个题结果是多少，谢谢！

[wuyq11]

ref 关键字使参数按引用传递。当控制权传递回调用方法时，在方法中对参数所做的任何更改都将反映在该变量中
out 关键字会导致参数通过引用来传递。

[lyl1599]

简单点写
hello,
hello,change2
hello,change2
hello,change2change3

[try_best7]

s1 after call to change2 is hello,
s1 after call to change2 is hello,change2
s1 after call to change2 is hello,change2
s1 after call to change2 is hello,change2change3

2楼正解

[vrhero]

又来了...去看看这个...

http://blog.csdn.net/vrhero/archive/2010/01/09/5166278.aspx

[zhang523012313]

s1 after call to change2 is hello,
s1 after call to change2 is hello,change2
s1 after call to change2 is hello,change2
s1 after call to change2 is hello,change2change3

LZ 给分