What is the use of having "ref" in this case

Question

Hi, 

 

I came across a question which made me confused. What is the use of having "ref" before s.MyFun in this case. I tried to remove it and it still works. 

 

I understand the reason for putting it before a variable that the content can be changed subsequently. What is the use of this one ? the function content will not be changed.  

 

class Sample 

{    

   public void MyFun(int i, Single j)     

   {         

       Console.WriteLine("Welcome to IndiaBIX !");     

   } 

}

delegate void del(int i, Single j); 

del d; Sample s = new Sample(); 

d = new del(ref s.MyFun); 

d(10, 1.1f);