Part 17 - C# Tutorial - Call By Reference

C# provides a ref keyword to pass argument as reference-type. It passes reference of arguments to the function rather than copy of original value. The changes in passed values are permanent and modify the original variable value.

C# Call By Reference Example

1. using System;  
2. namespace CallByReference  
3. {  
4.     class Program  
5.     {  
6.         // User defined function  
7.         public void Show(ref int val)  
8.         {  
9.              val *= val; // Manipulating value  
10.             Console.WriteLine("Value inside the show function "+val);  
11.             // No return statement  
12.         }  
13.         // Main function, execution entry point of the program  
14.         static void Main(string[] args)  
15.         {  
16.             int val = 50;  
17.             Program program = new Program(); // Creating Object  
18.             Console.WriteLine("Value before calling the function "+val);  
19.             program.Show(ref val); // Calling Function by passing reference            
20.             Console.WriteLine("Value after calling the function " + val);  
21.         }  
22.     }  
23. }  

Output:

Value before calling the function 50
Value inside the show function 2500
Value after calling the function 2500