Tutorials Modern JavaScript (ES6+) for Beginners

Default Parameters & Object Shorthand

Learn Default Parameters & Object Shorthand in our free Modern JavaScript (ES6+) for Beginners series. Step-by-step explanations, examples, and interview tips on Toolliyo Academy.

5 min read Updated 7/18/2026

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Course: Modern JavaScript (ES6+) for Beginners · Lesson: 7/12 · Read time: ~14 min · Level: Beginner · ES version: ES2015 (ES6) and above

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');
  }
};

🌍 Real-world example — Send email with optional CC

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.'
});

⚠️ Common Mistake: Default only triggers for undefined, not null: fn(null) does not use default — pass undefined or omit the argument.

👨‍🏫 Teaching note: Quiz: what does greet(name = "Guest") return when called with greet("")? Empty string — default not used.