jmartin-20100706-0.txt

Blog Title:  JavaScriptness.prototype = new Class(); From Classical to Prototypal
Author:      Justin Martin
Date:        July 7th, 2010

jmartin-20100706-1.js

function Square (side) {
  this.side = side;
};

Square.prototype.area = function () {
  return this.side * this.side;
};

Square.prototype.perimeter = function () {
  return this.side * 4;
};

var mySquare = new Square (5);

jmartin-20100706-2.js

function ContainerSquare (side, contents) {
  this.superclass(side);
  this.contents = contents;
};

ContainerSquare.prototype = new Square();
ContainerSquare.prototype.superclass = Square;
ContainerSquare.prototype.constructor = ContainerSquare;

ContainerSquare.prototype.getContents = function () {
  return this.contents;
};

var myContainer = new ContainerSquare(6, "X");

jmartin-20100706-3.js

var firstSquare = {
  side: 5,
  area: function () {
    return this.side * this.side;
  },
  perimeter: function () {
    return this.side * 4;
  }
};

jmartin-20100706-4.js

if (typeof Object.beget !== 'function') {
  Object.beget = function (o) {
    var F = function () {};
    F.prototype = o;
    return new F();
  }
}

var secondSquare = Object.beget(firstSquare);

secondSquare.side = 6;

jmartin-20100706-5.js

var squareMaker = function(side) {
  return {
    getSide: function() {
      return side;
    },
    area: function () {
      return side * side;
    },
    perimeter: function () {
      return side * 4;
    }
  };
};

var anotherSquare = squareMaker(5);

jmartin-20100706-6.js

var containerMaker = function(side, contents) {
  var container = squareMaker(side);
  container.getContents = function () {
    return contents;
  };
  return container;
};

var anotherContainer = containerMaker(6, "O");