예제 #1
0

//猪八戒类

class Pig{
	public function display(){
		echo '猪八戒下凡，哼哼坠地! <br/>';
	}
}

//main

//打开蓝灯
$light = new Light();
$blueglass = new BlueGlass();
$light->TrunOn($blueglass);


//打开绿灯
$greenglass = new GreenGlass();
$light->TrunOn($greenglass);

//坏了猪八戒从手电筒里面出生了, 现在做了类型限制

$pig = new Pig(); 
$light->TrunOn($pig);  //Catchable fatal error: Argument 1 passed to Light::TrunOn() must be an instance of BlueGlass

/****
如果按PHP本身特点,不检测类型,
本身就可以说是多态的,甚至变态的.
예제 #2
0

//猪八戒类

class Pig{
	public function display(){
		echo '猪八戒下凡，哼哼坠地! <br/>';
	}
}

//main

//打开红灯
$light = new Light();
$redglass = new RedGlass();
$light->TrunOn($redglass);


//打开绿灯
$greenglass = new GreenGlass();
$light->TrunOn($greenglass);


//坏了猪八戒从手电筒里面出生了

$pig = new Pig();
$light->TrunOn($pig);
/*****
分析 与java那段出错程序相比
php没报错,
因为PHP是弱类型动态语言.