Understanding C#'s String.Intern() Method: Managing String References in Memory

Learn about C#'s `String.Intern()` method and how it manages string references in the intern pool to improve performance in applications dealing with many strings. This guide explains its functionality, use cases, and implications for memory management.

Understanding C#'s `String.Intern()` Method

The C# `String.Intern()` method manages a pool of string references in memory (the "intern pool"). It's designed for efficiency when dealing with many strings, particularly if you're comparing strings frequently.

How `String.Intern()` Works

When you call `String.Intern(str)`, the method checks if a string equal to `str` already exists in the intern pool. If a match is found, it returns a reference to that existing string in the pool. If no match is found, it adds a new entry for `str` to the pool and returns a reference to that newly added string.

`String.Intern()` Signature

public static string Intern(string str);

The method takes a string as input and returns a string (a reference to the string in the intern pool).

Example

using System;

public class StringExample {
    public static void Main(string[] args) {
        string s1 = "Hello World";
        string s2 = string.Intern(s1);
        Console.WriteLine(s1); // Output: Hello World
        Console.WriteLine(s2); // Output: Hello World
    }
}

In this example, `s1` and `s2` will refer to the same string object in the intern pool after the `Intern()` call. This is because the string "Hello World" already exists in the pool.