Objects are passed by reference. : Parameter Reference : Language Basics C# Examples

    
using  System;  
  
class  Test  {  
    public  int  a,  b;  
  
    public  Test(int  i,  int  j)  {  
        a  =  i;  
        b  =  j;  
    }  
  
    /*  Now,  ob.a  and  ob.b  in  object  
          used  in  the  call  will  be  changed.  */  
    public  void  change(Test  ob)  {  
        ob.a  =  ob.a  +  ob.b;  
        ob.b  =  -ob.b;  
    }  
}  
  
class  MainClass  {  
    public  static  void  Main()  {  
        Test  ob  =  new  Test(15,  20);  
  
        Console.WriteLine("ob.a  and  ob.b  before  call:  "  +  
                                              ob.a  +  "  "  +  ob.b);  
  
        ob.change(ob);  
  
        Console.WriteLine("ob.a  and  ob.b  after  call:  "  +  
                                              ob.a  +  "  "  +  ob.b);  
    }  
}