Swap two references. : Ref : Language Basics C# Examples

    
using  System;  
  
class  RefSwap  {  
    int  a,  b;  
      
    public  RefSwap(int  i,  int  j)  {  
        a  =  i;  
        b  =  j;  
    }  
  
    public  void  show()  {  
        Console.WriteLine("a:  {0},  b:  {1}",  a,  b);  
    }  
  
    //  This  method  changes  its  arguments.  
    public  void  swap(ref  RefSwap  ob1,  ref  RefSwap  ob2)  {  
        RefSwap  t;  
    
        t  =  ob1;  
        ob1  =  ob2;  
        ob2  =  t;  
    }  
}  
  
class  MainClass  {  
    public  static  void  Main()  {  
        RefSwap  x  =  new  RefSwap(1,  2);  
        RefSwap  y  =  new  RefSwap(3,  4);  
  
        Console.Write("x  before  call:  ");  
        x.show();  
  
        Console.Write("y  before  call:  ");  
        y.show();  
  
        Console.WriteLine();  
  
        //  exchange  the  objects  to  which  x  and  y  refer  
        x.swap(ref  x,  ref  y);    
  
        Console.Write("x  after  call:  ");  
        x.show();  
  
        Console.Write("y  after  call:  ");  
        y.show();  
  
    }  
}