Default Parameters & Object Shorthand

ES6 lets you give function parameters default values and write shorter object literals. Less boilerplate, fewer if (x === undefined) checks.

Default parameters

function createUser(name, role = 'student', active = true) {
  return { name, role, active };
}

createUser('Alex');                    // role student, active true
createUser('Admin', 'admin');          // active still true
createUser('Guest', 'guest', false);

Object property shorthand

const name = 'Node.js Chat Course';
const price = 499;
const currency = 'INR';

// Old
const product1 = { name: name, price: price, currency: currency };

// ES6 shorthand
const product2 = { name, price, currency };

Method shorthand in objects

const api = {
  baseUrl: 'https://api.toolliyo.com',
  getHealth() {
    return fetch(this.baseUrl + '/health');
  }
};

function buildEmail({ to, subject, body, cc = [] }) {
  return { to, subject, body, cc, sentAt: new Date().toISOString() };
}

buildEmail({
  to: 'student@example.com',
  subject: 'Welcome to Toolliyo',
  body: 'Start with ES6 lesson 1.'
});