factoryFunctionExample.js

function objectFactory() {
  return {
    property1: 'My first property',
    property2: 'My second property',

    printProperties() {
      for (let prop in this) {
        if (typeof this[prop] !== 'function') {
          console.log(`${prop}: ${this[prop]}`);
        }
      }
    }
  };
}

let object = objectFactory();
let object1 = objectFactory();

console.log(object);
console.log(object1);

/*
{
  property1: 'My first property',
  property2: 'My second property',
  printProperties: [Function: printProperties]
}
{
  property1: 'My first property',
  property2: 'My second property',
  printProperties: [Function: printProperties]
}
*/

console.log(Object.getPrototypeOf(object) === Object.prototype); // true
console.log(Object.getPrototypeOf(object1) === Object.prototype); // true

console.log(object instanceof objectFactory); // false
Object.setPrototypeOf(object, objectFactory.prototype);
console.log(object instanceof objectFactory); // true