本文不再贅述html' target='_blank'>面向?qū)ο?/u>的知識(shí)，本文著重說明PHP的構(gòu)造函數(shù)。
php類的構(gòu)造函數(shù)可以是魔術(shù)魔方__construct() 也可以是和類同名的函數(shù)，實(shí)例如下：

 class A{    public function A(){        echo 'A is constructing...';    }  } class B{    public function __construct(){        echo 'B is contructing...';    } } $a = new A();   // A is constructing... $b = new B();   // B is constructing...

此外，在繼承時(shí)，應(yīng)該注意的是：
【子類可以不寫構(gòu)造函數(shù)，那么使用父類的構(gòu)造函數(shù)】

 class A{    protected $name;    public function A(){        echo 'A is constructing...<br>';    }    public function set_name($name){        $this->name = $name;    }    public function get_name(){        return $this->name;    } } class B extends A{    /*    public function __construct(){        echo 'B is contructing...<br>';    }    */ } //$a = new A(); $b = new B();  // A is constructing... $b->set_name('zhangsan'); echo $b->get_name();

【子類如果寫了構(gòu)造函數(shù)，那么不會(huì)再調(diào)用父類的構(gòu)造函數(shù)了】

 class A{    protected $name;    public function A(){        echo 'A is constructing...<br>';    }    public function set_name($name){        $this->name = $name;    }    public function get_name(){        return $this->name;    } } class B extends A{    public function __construct(){        echo 'B is contructing...<br>';    } } //$a = new A(); $b = new B(); // just echo 'B is contructing...' $b->set_name('zhangsan'); echo $b->get_name(); // zhangsan

【父類的構(gòu)造函數(shù)如果是私有的，可以被繼承，但是子類必須有自己的構(gòu)造函數(shù)，并且明確寫出來】

 class A{    protected $name;    private function A(){        echo 'A is constructing...<br>';    }    public function set_name($name){        $this->name = $name;    }    public function get_name(){        return $this->name;    } } class B extends A{    public function __construct(){        echo 'B is contructing...<br>';    } } //$a = new A(); $b = new B(); // B is contructing... $b->set_name('zhangsan'); echo $b->get_name();  // zhangsan