Singleton example

Singleton.js

/**
* Singleton Pattern
* @returns {Object}
*/

let Planet;
{
  let instance;
  Planet = function () {

    if (instance) {
      return instance;
    }

    this.name = 'Sun';
    this.type = 'Star';
  }

  instance = this;
};

let sun = new Planet();
let star = new Planet();
console.log(sun === star); //True