Inheritance within object literals

Question

 function Car(model, color, power){
    this.model = model;
    this.color = color;
    this.power = power;
    this.is_working = true;
    this.sound = function(){
        console.log("Vrummm!");
    };
}
 function Car_optionals(){
     this.turbo_boost = true;
     this.extra_horsepower = 20;
     this.name_tag = "Badass";
 }

Car.prototype = new Car_optionals();
var Audi = {};
Audi.prototype = new Car();
console.log(Audi.is_working);

So i'm having this too classes Car and Car_optionals and I want the newly crated object Audi to inherit proprietyes from both Car and Car_optionals classes. It is posible to inherit proprietyes and methods within object literals?

Answer 1

It is posible to inherit proprietyes and methods within object literals?

Not yet, but with ES6, this will be possible:

var foo = {
    __proto__: bar
};

where bar becomes the prototype of foo .

However, I rather think you mean whether it's possible to create objects with a specific prototype. You can use Object.create for that:

var foo = Object.create(bar);

Or if you have an already existing object, you can use Object.setPrototypeOf :

foo.setPrototypeOf(bar);

In your specific case though, there is no value in setting the prototype of Audi to anything, because Car and Car_optionals don't define anything on their prototype objects. Everything is set inside the functions itself, so you simply have to apply those functions to Audi :

Car.call(Audi, 'A4', 'blue', 180);
Car_optionals.call(Audi);

And the more natural way would be to create a new instance through Car :

var Audi = new Car('A4', 'blue', 180);
Car_optionals.call(Audi);