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Understanding Objects

Explore how JavaScript objects store data with key-value pairs, access and modify properties using dot and bracket notation, and utilize built-in methods like Object.keys and Object.freeze. Understand techniques to manipulate objects efficiently and practice best coding practices to handle data in your web projects.

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Objects in JavaScript are versatile data structures that allow us to store and organize data as key-value pairs. A key is a unique identifier (usually a string or symbol), and its associated value can be any JavaScript data type, including numbers, strings, arrays, other objects, or functions.

Creating an object

The syntax for defining objects in JavaScript is given below.

const objectName = {
  key1: value1,
  key2: value2,
  key3: value3
};
Syntax for objects in JavaScript

Let’s create a car object to illustrate how objects work:

const car = {
  brand: "Toyota",
  model: "Corolla",
  year: 2022,
  start: function() {
    console.log("Car started!");
  }
};
Creating a car object in JavaScript

In the above code:

  • Properties: The brand, model, and year are key-value pairs.

  • Method: The start is a function that belongs to the car object.

We can access the data stored in these objects in the following ways.

  • Dot notation: car.brand returns ...