009-对象—— 构造方法__construct析构方法__destruct使用方法 PHP重写与重载

<?php
/**构造方法__construct析构方法__destruct使用方法 PHP重写与重载
 */
//构造方法：当实例化对象时，自动运行的方法
/*class channel{
    function __construct()
    {
        echo 222;
    }
}
$channel=new channel();//输出：222*/

/*class db{
    private $host;
    private $user;
    private $pwd;
    private $dbname;
    private $mysqli;
    function __construct()
    {
        include 'dbConfig.php';
        $this->host=HOST;
        $this->user=USER;
        $this->pwd=PWD;
        $this->dbname=DBNAME;
        $this->_connect();
    }
    function _connect(){
        $this->mysqli=new mysqli($this->host,$this->user,$this->pwd,$this->dbname);
    }
}
$chanel=new db();*/

//
/*浏览器输入：
http://phpbasic.com/004object/9.php?&access=admin&a=_display
输出：显示栏目
*/
/*class channel{
    function __construct()
    {
        $access=$_GET['access'];//保存用户权限：
        if ($access=="admin"){
            $method=$_GET['a'];
            $this->$method();
        }
    }
    function _edit(){
        echo "编辑栏目";
    }
    function _del(){
        echo "删除栏目";
    }
    function _display(){
        echo "显示栏目";
    }
}
$channel=new channel();*/

//通过构造函数，对对象进行整体的配置：
/*class APP{
    function __construct()
    {
        self::_include();
        self::_config();
    }
    static function _config(){
        echo "<br/>配置环境......<br/>";
    }
    static function _include(){
        echo "<br/>载入文件...<br/>";
    }
    function display($content){
        echo "<h1 style='color: #333; border: 3px #F00 solid;'>$content</h1>";
    }
    public function dump($content){
        echo "<pre>";
        print_r($content);
    }
}

class channel extends APP{
    function __construct()
    {
        parent::__construct();
        $access=$_GET['access'];//保存用户权限：
        if ($access=="admin"){
            $method=$_GET['a'];
            $this->$method();
        }else{
            $this->display("你没有权限，不能操作栏目");
        }
    }
    function _edit(){
        echo "编辑栏目";
    }
    function _del(){
        echo "删除栏目";
    }
    function _display(){
        echo "显示栏目";
    }
}
$channel=new channel();*/

//析构方法:
/*class db{
    private $host;
    private $user;
    private $pwd;
    private $dbname;
    private $mysqli;
    function __construct()
    {
        include 'dbConfig.php';
        $this->host=HOST;
        $this->user=USER;
        $this->pwd=PWD;
        $this->dbname=DBNAME;
        $this->_connect();
    }
    function _connect(){
        $this->mysqli=new mysqli($this->host,$this->user,$this->pwd,$this->dbname);
    }
    function update(){
        echo "更新数据";
    }
    function insert(){
        echo "插入数据";
    }
    public function _close(){
        echo "关闭数据库";
    }
    function __debugInfo()
    {
        //对象执行完之后执行的一些方法：
        $this->_close();
    }
}
$chanel=new db();*/

//类的重写：（利用重写可以实现多态的实现）
class dongwu
{
    function yundong()
    {
        echo "动物在跑";
    }
}

class yu extends dongwu
{
    function yundong()
    {
        echo "鱼在游";
    }
}

class niao extends dongwu
{
    function yundong()
    {
        echo "飞。。。。";
    }
}
class gou extends dongwu{

}

class chongwu
{
    private $congwu;

    function __construct($type)
    {
        $this->congwu = new $type();
    }

    function yundong()
    {
        $this->congwu->yundong();
    }
}

$congwu = new chongwu('yu');
$congwu->yundong();