Rediscovering JavaScript

Defining a Method

Methods are an integral part of classes. They exhibit behavior and are often used to perform some action, and possibly to effect state change.

To define a method, place the function body within the {} of the class definition—but without the function keyword. Let’s rewrite the Car class, this time adding another field and a method.

classes/create-method.js

class Car {
  constructor(year) {
    this.year = year;
    this.miles = 0;
  }

  drive(distance) {
    this.miles += distance;
  }
}

In the constructor we initialized this.year to the value received in the year parameter and initialized this.miles to a value of 0. In the drive() method we increase the this.miles value by the value received in the distance parameter. ...