Detailed explanation of the three forms of sample code of PHP factory pattern

<?php
// 简单工厂模式
interface ICar {
	function run();
}

class BMWCar implements ICar {
	
	public function run() {
		echo &#39;bmw run!<br/>&#39;;
	}
}

class AuDiCar implements ICar {
	
	public function run() {
		echo &#39;audi run!<br/>&#39;;
	}
}

/**
 * 简单工厂
 */
class FactorySimple {
	
	/*
	public static function createBmw() {
		return new BMWCar();
	}
	
	public static function createAudi() {
		return new AuDiCar();
	}
	*/
	
	public static function createCar($type) {
		switch($type) {
			case &#39;bmw&#39;:
				return new BMWCar();
			case &#39;audi&#39;:
				return new AuDiCar();
			default:
				throw new Exception(&#39;type error!&#39;);
		}
	}
}


// ------------------------------------------------------
// ------------------------------------------------------

// 工厂方法模式
interface CreateCar { //工厂类接口
	function create();
}

/**
 * bmw car factoyr
 */
class BmwFactory implements CreateCar {
	
	public function create() {
		return new BMWCar();
	}
}

/**
 * audi car factory
 */
class AuDiFactory implements CreateCar {
	
	public function create() {
		return new AuDiCar();
	}
}

// ------------------------------------------------------
// ------------------------------------------------------

// 抽象工厂模式

class WhiteBMWCar implements ICar {
	
	public function run() {
		echo &#39;white bmwcar run!<br/>&#39;;
	}
}

class BlackBMWCar implements ICar {
	
	public function run() {
		echo &#39;black bmwcar run!<br/>&#39;;
	}
}

class WhiteAuDiCar implements ICar {
	
	public function run() {
		echo &#39;white audicar run!<br/>&#39;;
	}
}

class BlackAuDiCar implements ICar {
	
	public function run() {
		echo &#39;black audicar run!<br/>&#39;;
	}
}

// 提供一系列的接口
interface ICarCreate {
	function createBmw();
	function createAuDi();
}

/**
 * create white car
 */
class WhiteCarFactory implements ICarCreate {
	
	// white bmw
	public function createBmw() {
		return new WhiteBMWCar();
	}
	
	// white audi
	public function createAuDi() {
		return new WhiteAuDiCar();
	}
}

/**
 * create black car
 */
class BlackCarFactory implements ICarCreate {
	
	// black bmw
	public function createBmw() {
		return new BlackBMWCar();
	}
	
	// black audi
	public function createAuDi() {
		return new BlackAuDiCar();
	}
}