CSE 121B: JavaScript Language

Objects

Overview

JavaScript objects are a way to group related data and functions together. Objects are a core concept in JavaScript and are used extensively in the language. In this learning activity, you will learn how to create and use objects in JavaScript.

"An object is a collection of related data and/or functionality. These usually consist of several variables and functions (which are called properties and methods when they are inside objects)." - MDN Web Docs

Prepare

Here's an example of a JavaScript object representing a person: 

let person = {
  name: "Antonia Francesca",
  age: 30,
  profession: "Software Engineer",
  hobbies: ["reading", "playing guitar", "hiking"],
  address: {
    street: "123 Camino Real",
    city: "Santa Rosa",
    country: "Honduras"
  },
  isEmployed: true,
  greet: function() {
    console.log(`Hello, my name is ${this.name}.`);
  }
};

In this example, the person object has various properties such as name, age, profession, hobbies, address, and isEmployed. It also includes a greet method that logs a greeting message to the console using the person's name.

The address property is an object itself, containing nested properties such as street, city, and country.

You can access and modify the properties and invoke the methods of the person object using dot notation or bracket notation. For example:

console.log(person.hobbies[0]); // Output: reading

Check Your Understanding