Inheritance | Object-Oriented JavaScript

Using a Mix of Prototypal Inheritance and Copying Properties

When you use inheritance, you will most likely want to take some existing functionality and then build upon it. This means creating a new object by inheriting from an existing object and then adding some additional methods and properties. You can do this with one function call, using a combination of the last two approaches just discussed.

You can:

Use prototypal inheritance to clone an existing object

Copy all of the properties of another object

function objectPlus(o, stuff) {
  var n;
  function F() {}
  F.prototype = o;
  n = new F();
  n.uber = o;

  for (var i in stuff) {
    n[i] = stuff[i];
  }
  return n;
}

This function takes an object o to inherit from and another object stuff that has the additional methods and properties that are to be copied. Let's see this in action.

Start with the base shape object:

var shape = {
  name: 'shape',
  toString: function() {return this.name;}
};

Create a 2D object by inheriting shape...

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Object-Oriented JavaScript

Object-Oriented JavaScript

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