面向对象 继承

<?phpheader("Content-Type: text/html; charset=utf-8");class person{public $name;public $age;public $sex;public function __construct($name,$age,$sex){$this -> name = $name;$this -> age = $age;$this -> sex = $sex;}public function say(){echo 'say...';}}class teacher extends  person{//私有方法public function teach (){echo '上课';}}$teacher = new teacher('娜美',30,'女');$teacher -> say();//公有方法$teacher -> teach();//私有方法?>

<?phpheader("Content-Type: text/html; charset=utf-8");class A{public $name = "娜美";public $age = 20;public function say(){return $this -> name;}}/* * php 是单继承 一个类只能有一个父类 * 一个类可以有多个子类 * 支持多层继承 */class B extends A{}class C extends B{}$b = new B();echo $b -> say();print_r($b);echo "<hr/>";$c = new C();echo $c -> say();print_r($c);?>