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JavaScript Object-Oriented JavaScript (2015) Practice Project Object-Oriented JavaScript Review

Posted by Yuval Blass
Yuval Blass
18,134 Points

A question about prototype...

Hi everyone,

I finished the Object Oriented js course a moment ago, and I have a question; When we use x.prototype = Object.create(X)? Actually, What does it do?

Best,
Yuval Blass.

1 Answer

Charles Kenney
Charles Kenney
15,604 Points
Charles Kenney
Charles Kenney
15,604 Points

You can think of prototype as a property of a given object. It, itself is an object, which describes the prototypal methods and properties of the actual object model. The easiest way to explain this is to try it in the browser. Open up the javascript console in chrome and try the following:

// An Object
function MyObject() {
    this.foo = 'bar';
}

// A Prototype Method
MyObject.prototype.bar = function() {
    return 'foo' + this.foo;
}

MyInheritedObject = Object.create(MyObject.prototype);
console.log(MyObject);

As a result, you should see an object of the following shape in your console:

MyObject {
    __proto__: {
        bar: function(),
        constructor: function MyObject(),
        __proto__: Object
    }
}

There you can see the method we defined, and the constructor function. This is what you are assigning to your inherited object's prototype property.

Hope this helps,

  • Charles