Name: Object creation - JavaScript Challenges
Rating: 3.4 (9141 reviews)
Author: mitchell_cheng

You can find all the code in this post at repo Github.

Object creation methods

Constructor-based

Recommend before ES6.

/**
 * @param {string} firstName
 * @param {string} lastName
 * @param {number} age
 */

function Person(firstName, lastName, age) {
  this.firstName = firstName;
  this.lastName = lastName;
  this.age = age;
  this.greet = function () {
    console.log(`Hello, my name is ${this.firstName} ${this.lastName}`);
  };
}

// Usage example
const person1 = new Person("John", "Doe", 30);
person1.greet(); // => Hello, my name is John Doe

const person2 = new Person("Jane", "Smith", 25);
person2.greet(); // => Hello, my name is Jane Smith

Class-based

Recommend after ES6.

class Person {
  constructor(firstName, lastName, age) {
    this.firstName = firstName;
    this.lastName = lastName;
    this.age = age;
  }

  greet() {
    console.log(`Hello, my name is ${this.firstName} ${this.lastName}`);
  }
}

// Usage example
const person1 = new Person("John", "Doe", 30);
person1.greet(); // => 'Hello, my name is John Doe'

const person2 = new Person("Jane", "Smith", 25);
person2.greet(); // => 'Hello, my name is Jane Smith'

Object initializer

const person = {
  firstName: "John",
  lastName: "Doe",
  age: 30,
  greet: function () {
    console.log(`Hello, my name is ${this.firstName} ${this.lastName}`);
  },
};

person.greet(); // => 'Hello, my name is John Doe'

`Object.create()`

const personPrototype = {
  greet: function () {
    console.log(`Hello, my name is ${this.firstName} ${this.lastName}`);
  },
};

const person = Object.create(personPrototype);
person.firstName = "John";
person.lastName = "Doe";

// Usage example
person.greet(); // => 'Hello, my name is John Doe'

Factory Pattern

/**
 * @param {string} firstName
 * @param {string} lastName
 * @param {number} age
 * @return {object}
 */

function createPerson(firstName, lastName, age) {
  return {
    firstName: firstName,
    lastName: lastName,
    age: age,
    greet: function () {
      console.log(`Hello, my name is ${this.firstName} ${this.lastName}`);
    },
  };
}

// Usage example
const person1 = createPerson("John", "Doe", 30);
person1.greet(); // => 'Hello, my name is John Doe'

const person2 = createPerson("Jane", "Smith", 25);
person2.greet(); // => 'Hello, my name is Jane Smith'

Object creation - JavaScript Challenges