Call By Reference

On passing variables in a function, any changes made in the passed parameter will update the original variable’s reference too. To pass an argument as reference-type instead of the copy of the original value, i.e, to pass a reference of arguments to the function the ref keyword is used in C#.

Features of call by reference

• Changes in one object variable affect the other object variable.
• Actual and copied variables are created in the same memory location.

using System;  
namespace MyApplication
{  
    class Test  
    {  
        public void Display(ref int x)  
        {  
             x += x;  
            Console.WriteLine("Value inside the function: "+ x);  
        }  
        static void Main(string[] args)  
        {  
            int x = 200;  
            Test abc = new Test(); 
            Console.WriteLine("Value before calling: "+ x);  
            abc.Display(ref x);            
            Console.WriteLine("Value after calling: " + x);  
        }  
    }  
}

OUTPUT

Value before calling: 200
Value inside the function: 400
Value after calling: 400