JavaScript Objects: Properties and Methods

Understand JavaScript objects, properties, methods, dot notation and bracket notation with beginner-friendly examples.

Describe a value with properties

An object groups related information using named properties. This example describes one book:

const book = {
  title: "Small Web Projects",
  pages: 180,
  available: true
};

Read and update properties

Use dot notation when the property name is known in your code. Bracket notation is useful when the property name is stored in a variable.

console.log(book.title);
book.available = false;

const field = "pages";
console.log(book[field]);

Add a method

A method is a function stored as an object property. It can use this to refer to the object that owns it.

const user = {
  name: "Sam",
  greet() {
    return `Hello, ${this.name}`;
  }
};