php设计模式的六大原则（五）：依赖倒置原则

 run();	}}class Client{		public static function doing(){			$driver = new Driver();		$driver -> drive( new Benz() );	}}Client :: doing();// 那么如果司机想开宝马呢？，是不是就要修改Driver了，这就违反了开闭原则了，怎么能只在Client添加代码就让宝马车也会开呢？interface ICar{		//定义一个汽车接口	public function run();}class BMW implements ICar{	public function run(){			return "BMW is runing !!!";	}}class Benz implements ICar{	public function run(){			return "Benz is runing !!!";	}}interface IDriver{		//定义一个司机接口，以防以后有A照，B照，C照的	public function drive(ICar $car);}class Driver implements IDriver{	public function drive(ICar $car){			echo "
" . $car -> run();	}}class Client{	public static function doing(){			$driver = new Driver();		$driver -> drive( new BMW() ); //开宝马		$driver -> drive( new Benz() ); //开奔驰	        .	        .	        .	        .	}}Client :: doing();?>

这么简单，学会了吧？依赖倒置原则核心一句话：面向接口编程。