PHP 类的继承

一个父类，一个子类(People.php):

<?php
class People {
    private $name;
    private $age;
    function __construct() {
        // 构造方法
        $this->age = 20;
        $this->name = "noname";
    }
    function __destruct() { // 析构方法，因为PHP的特性，页面载入完就会销毁所有对象
        echo "销毁对象" . $this->name;
    }
    /**
     * setter和getter
     *
     * @return the $name
     */
    public function getName() {
        return $this->name;
    }
    
    /**
     *
     * @return the $age
     */
    public function getAge() {
        return $this->age;
    }
    
    /**
     *
     * @param field_type $name        	
     */
    public function setName($name) {
        $this->name = $name;
    }
    
    /**
     *
     * @param field_type $age        	
     */
    public function setAge($age) {
        $this->age = $age;
    }
    public function say() {
        echo $this->name. $this->age;
    }

}
class Student extends People {
    //继承People
    public $id;
    public function study() {
        echo "我在学习";
    }
    
    public function say() {
        echo parent::getName().parent::getAge().$this->id;
        //访问父类方法读取
        
    }

}
?>

使用:

<?php
require_once 'People.php';
$stu=new Student();
$stu->setAge(23);
$stu->setName("张三");
$stu->id=232432;
$stu->say();
$stu->study();
?>