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JavaScript JavaScript Foundations Objects Prototypes

Mark Bradshaw
PLUS
Mark Bradshaw
Courses Plus Student 7,658 Points
Posted by Mark Bradshaw
Mark Bradshaw
Courses Plus Student 7,658 Points

Still can't get throughh a javascript quiz question. Please advise.

Here;s the question: Modify the Car's prototype to have 'wheels' set to 4.

Here's the code before my answer: <script> var carPrototype = { model: "generic", currentGear: 0, increaseGear: function() { this.currentGear ++; }, decreaseGear: function() { this.currentGear--; } } function Car(model) { this.model = model; } Here's my answer to the question: Car.prototype.wheels = 4;

Jason Anello
Jason Anello
Courses Plus Student 94,610 Points

Mark,

You had 2 people trying to help you in your other question about this. You didn't need to double post your question.

1 Answer

Patrick Johnson
Patrick Johnson
9,505 Points
Patrick Johnson
Patrick Johnson
9,505 Points

It's asking for the car prototype. Which is the first variable that is created (in this case: var carPrototype). You need to modify that to include the set of wheels any new car created from that prototype will have.

So, the prototype should be: 

var carPrototype = { 
    model: "generic", 
    currentGear: 0, 
   // include the wheels here
   wheels: 4,
    increaseGear: function() { this.currentGear ++; }, 
    decreaseGear: function() { this.currentGear--; } 
}

If you wanted to modify your prototype after the fact (lets pretend you forgot to add it originally) you can do this. 

carPrototype.wheels = 4;

That way, when you run anything that uses the prototype, it'll inherently have 4 wheels.