Creating objects
Learn to create objects with key-value pairs using object literals.
Object literal
In JavaScript, an object groups several values into one container. Each value is labeled with a key, written as a key-value pair.
You create an object literal with curly braces:
const user = {
name: 'Alex',
age: 28
};Here name and age are keys; 'Alex' and 28 are their values. Keys are usually written without quotes.
Different types in properties
An object's values can be of different data types: string, number, boolean, array, even another object.
const product = {
name: 'Pen',
price: 25,
inStock: true,
tags: ['stationery', 'office']
};Each property keeps its own type. price is a number, inStock is a boolean, and tags is an array. This flexibility makes objects ideal for modeling real-world data.
Exercise Create a book object
Create an object named book. It should have title set to 'Lord of the Rings', pages set to 1178 and read set to false.
Show example solution
const book = {
title: 'Lord of the Rings',
pages: 1178,
read: false
};Test yourself
-
Which is a valid object literal?
// A const a = [1, 2, 3]; // B const b = { name: 'Alex' }; // C const c = (name: 'Alex'); // D const d = < name: 'Alex' >;- A
- B
- C
- D
Show answer
B — Correct! Curly braces form an object literal.
-
Create an empty object
const empty = ____;Show answer
const empty = {}; -
Match keys to their values
- name
- 'Alex'
- age
- 28
- active
- true