Google trends Public Holidays Coupon Code Code Compiler

Implementing the Singleton Design Pattern in Nodejs

Sep 11, 2023

In Node.js, the Singleton pattern can be used to ensure that a class has only one instance, and that instance is shared across different parts of your application. This can be useful when you want to centralize access to a resource or configuration that should be shared among different modules or components.

Here's an example of how to implement the Singleton pattern in Node.js:

// Singleton.js

class Singleton {
  constructor() {
    if (!Singleton.instance) {
      // Create a new instance if it doesn't exist = [];
      Singleton.instance = this;

    return Singleton.instance;

  // You can add methods and properties to the singleton instance
  addItem(item) {;

  getItems() {

// Export the Singleton instance
module.exports = new Singleton();

In this example, we create a Singleton class with a private instance property. When you create a new instance of the Singleton class, it checks whether an instance already exists. If an instance exists, it returns the existing instance; otherwise, it creates a new one.

Now you can use the Singleton in different parts of your Node.js application like this:

// ModuleA.js
 const singlet

singletonInstance.addItem('Item A from ModuleA');

// ModuleB.js
 const singlet

singletonInstance.addItem('Item B from ModuleB');

// Main.js
 const singlet


Copyright 2024. All rights are reserved