OO JavaScript

OO.js

function Car (doors, fuel, color) {

    this.doors = doors;
    this.color = color;
    this.fuel = fuel;

    this.changeFuel = function () {
        if (this.fuel === 'petrol') {
            this.fuel = 'diesel';
        } else {
            this.fuel = 'petrol';
        }
    }

}

var fiesta = new Car(5, 'petrol', 'red');
var skyline = new Car(4, 'petrol', 'black');

fiesta.doors === 5;
skyline.doors === 4;

skyline.changeFuel();
skyline.fuel === 'diesel'; // true

// prototype can be used to add additional methods to all instances of Car
Car.prototype.changeColor = function (color) { this.color = color };

fiesta.changeColor('white');
fiesta.color === 'white'; // true