JavaScript Classes

Introduced with ECMAScript 2015, or ES6, JavaScript Classes provide a way to create templates for JavaScript objects.

JavaScript Class Syntax

To define a class, use the class keyword. It is important to include a method called constructor() in every class:

class Car {
  constructor(name, year) {
    this.name = name;
    this.year = year;
  }
}

In the example above, a class named "Car" is created with two initial properties: "name" and "year". It's important to note that a JavaScript class is not an object itself but serves as a blueprint for creating objects.

Creating Objects with a Class

Once a class is defined, it can be used to instantiate objects:

let myCar1 = new Car("Ford", 2014);
let myCar2 = new Car("Audi", 2019);

In this example, two objects are created using the Car class, and the constructor method is automatically called to initialize these objects.

The Constructor Method

The constructor method is a special function that:

Must be named "constructor".
Executes automatically when a new object instance is created.
Initializes object properties.

If no constructor is defined, JavaScript provides an empty default constructor.

Class Methods

Methods within a class are defined similarly to other object methods. You can add as many methods as needed to your class. For instance, a method to calculate the age of a car could be added as follows:

class Car {
  constructor(name, year) {
    this.name = name;
    this.year = year;
  }

  age(currentYear) {
    return currentYear - this.year;
  }
}

Class methods can also accept parameters, allowing for more dynamic behavior.