C# | How to retrieve the system's reference to the specified String

Last Updated : 11 Jul, 2025

String.Intern(String) Method is used to retrieve the system's reference to the specified String. This method uses the intern pool to search for a string equal to the value of the specified string.
If such a string exists, then its reference in the intern pool is returned, or if the string doesn't exist, a reference of the specified string is added to the intern pool, then that reference is returned.
Here the intern pool is a table that contains a single reference to each unique literal string declared or created programmatically in your program.
Syntax:

public static string Intern (string strA);

Here strA is a string to search for in the intern pool.
Return Value: The return type of this method is System.String. This method will return a system's reference to strA if it is interned. Otherwise, a new reference to a string with the value of strA.
Exception: This method will give ArgumentNullException if the str is null.
Below given are some examples to understand the implementation in a better way:
Example 1:

CSharp

// C# program to illustrate Intern() method
using System;   
           
public class GFG    
{    
    
    // main method
    public static void Main(string[] args)    
    {    
       
        // string
       string strA = "This is C# tutorial";  
        
       // retrieve the system reference
       // of strA string by
       // using Intern() method
       string strB = string.Intern(strA);  
        
       // Display the strings
       Console.WriteLine(strA);  
       Console.WriteLine(strB);  
    }    
}

Output:

This is C# tutorial
This is C# tutorial

Example 2:

CSharp

// C# program to illustrate the 
// use of Intern() Method
using System;

class GFG {
    
    public static void Main()
    {

        // strings
        string strA = "GeeksforGeeks";
        string strB = "GFG";
        string strC = "Noida";
        string strD = String.Intern(strA);
        string strE = String.Intern(strC);

        // Display string
        Console.WriteLine("string A == '{0}'", strA);
        Console.WriteLine("string B == '{0}'", strB);
        Console.WriteLine("string C == '{0}'", strC);
        Console.WriteLine("string D == '{0}'", strD);
        Console.WriteLine("string E == '{0}'", strE);
        Console.WriteLine();

        // Check the reference of strings
        Console.WriteLine("Is string A have the same reference as string B: {0}",
                                                    (Object)strA == (Object)strB);
                                                    
        Console.WriteLine("Is string B have the same reference as string C: {0}", 
                                                    (Object)strB == (Object)strC);
                                                    
        Console.WriteLine("Is string D have the same reference as string E: {0}",
                                                    (Object)strD == (Object)strE);
                                                    
        Console.WriteLine("Is string A have the same reference as string D: {0}",
                                                    (Object)strA == (Object)strD);
                                                    
        Console.WriteLine("Is string E have the same reference as string C: {0}",
                                                    (Object)strE == (Object)strC);
    }
}

Output:

string A == 'GeeksforGeeks'
string B == 'GFG'
string C == 'Noida'
string D == 'GeeksforGeeks'
string E == 'Noida'

Is string A have the same reference as string B: False
Is string B have the same reference as string C: False
Is string D have the same reference as string E: False
Is string A have the same reference as string D: True
Is string E have the same reference as string C: True

Reference:

https://learn.microsoft.com/en-us/dotnet/api/system.string.intern?view=netframework-4.7.2#definition

C# | How to retrieve a reference to a specified String

ankita_saini

Improve

Article Tags :

C# | How to retrieve the system's reference to the specified String

Similar Reads

Thank You!

What kind of Experience do you want to share?