factory/factory.html

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Factory</title>
</head>
<body>
<script>
function CarMaker(){};

CarMaker.prototype.drive = function(){
	return 'Vroom, I have ' + this.doors + ' doors';
};

CarMaker.factory = function(type){
	var constr = type,
		newcar;

	if(typeof CarMaker[constr] !== 'function'){
		throw {
			name: 'Error',
			message: constr + ' does not exist'
		};
	}

	if(typeof CarMaker[constr].prototype.drive !== 'function'){
		CarMaker[constr].prototype = new CarMaker();
	}

	newcar = new CarMaker[constr]();
	return newcar;
};


CarMaker.Compact = function(){
	this.doors = 4;
};

CarMaker.Convertible = function(){
	this.doors = 2;
};

CarMaker.SUV = function(){
	this.doors = 24;
};

var corolla = CarMaker.factory('Compact');
var soltice = CarMaker.factory('Convertible');
var cherokee = CarMaker.factory('SUV');

console.log(corolla.drive()); //Vroom, I have 4 doors
console.log(soltice.drive()); //Vroom, I have 2 doors
console.log(cherokee.drive()); //Vroom, I have 24 doors

//Object建構式
var o = new Object(),
	n = new Object(1),
	s = new Object('1'),
	b = new Object(true);

console.log(o.constructor === Object); //true
console.log(n.constructor === Number); //true
console.log(s.constructor === String); //true
console.log(b.constructor === Boolean); //true
</script>
</body>
</html>