How to define Singleton in TypeScript

Question

What is the best and most convenient way to implement a Singleton pattern for a class in TypeScript? (Both with and without lazy initialisation).

Answer 1

You can also make use of the function Object.Freeze(). Its simple and easy:

class Singleton {

  instance: any = null;
  data: any = {} // store data in here

  constructor() {
    if (!this.instance) {
      this.instance = this;
    }
    return this.instance
  }
}

const singleton: Singleton = new Singleton();
Object.freeze(singleton);

export default singleton;