Inheritance patterns with constructor functions

inheritence.js

// here's a normal JavaScript constructor function

var Block = function(){
  this.width = 30;
  this.height = 50;
  this.otherthing = "whateverelse";
};

// these are class methods that all blocks inherit from
Block.prototype.doThing = function(){
  // business logic
};


// here's a subclass

var SquareBlock = function(){
  // apply all the properties on the parent onto this child
  Block.call(this);

  // you can set more properties here
  this.bismack = "Biyombo";

  // you can also overwrite previously set properies. This will apply to SquareBlock only, and not Block
  this.width = 50;
};

// inherit from the same class methods that Block inherits from, and set the .contructor property to refer to SquareBlock (it would default to Block)
SquareBlock.prototype = Object.create(Block.prototype);
SquareBlock.prototype.constructor = SquareBlock;

// you can continue to set methods here that only SquareBlock will inherit from
SquareBlock.prototype.spin = function(){
  // do stuff
}


// NOTE: you have to use the `new` keyword to create objects that inherit from these classes. e.g.
var foo = new Block();

var boo = new SquareBlock();