如何让PHP类构造函数调用父类的父类构造函数?

我需要在PHP中有一个类构造函数调用父类的父类的(祖父母?)构造函数，而不调用父类构造函数。

// main class that everything inherits
class Grandpa 
{
    public function __construct()
    {

    }

}

class Papa extends Grandpa
{
    public function __construct()
    {
        // call Grandpa's constructor
        parent::__construct();
    }
}

class Kiddo extends Papa
{
    public function __construct()
    {
        // THIS IS WHERE I NEED TO CALL GRANDPA'S
        // CONSTRUCTOR AND NOT PAPA'S
    }
}

我知道这是一件很奇怪的事情，我正试图找到一种不难闻的方法，但尽管如此，我很好奇这是否可能。

当前回答

<?php

class grand_pa
{
    public function __construct()
    {
        echo "Hey I am Grand Pa <br>";
    }
}

class pa_pa extends grand_pa
{
    // no need for construct here unless you want to do something specifically within this class as init stuff
    // the construct for this class will be inherited from the parent.
}

class kiddo extends pa_pa
{
    public function __construct()
    {
        parent::__construct();
        echo "Hey I am a child <br>";
    }
}

new kiddo();
?>

当然，这期望您不需要在pa_pa的构造中做任何事情。运行该命令将输出:

嘿，我是爷爷嘿，我是个孩子

2014-07-18 03:39:41

其他回答

    class Grandpa 
{
    public function __construct()
    {
        echo"Hello Kiddo";
    }    
}

class Papa extends Grandpa
{
    public function __construct()
    {            
    }
    public function CallGranddad()
    {
        parent::__construct();
    }
}

class Kiddo extends Papa
{
    public function __construct()
    {

    }
    public function needSomethingFromGrandDad
    {
       parent::CallGranddad();
    }
}

2015-08-26 16:56:44

从PHP 7你可以使用

家长:家长:__construct ();

2017-07-10 15:51:36

另一个不使用标志的选项可能适用于您的情况:

<?php
// main class that everything inherits
class Grandpa 
{
    public function __construct(){
        $this->GrandpaSetup();
    }

    public function GrandpaSetup(){
        $this->prop1 = 'foo';
        $this->prop2 = 'bar';
    }
}

class Papa extends Grandpa
{
    public function __construct()
    {
        // call Grandpa's constructor
        parent::__construct();
        $this->prop1 = 'foobar';
    }

}
class Kiddo extends Papa
{
    public function __construct()
    {
        $this->GrandpaSetup();
    }
}

$kid = new Kiddo();
echo "{$kid->prop1}\n{$kid->prop2}\n";

2009-10-13 00:37:06

关于php的有趣细节:扩展类可以在静态事务中使用父类的非静态函数。在外面你会得到一个严格的错误。

error_reporting(E_ALL);

class GrandPa
{
    public function __construct()
    {
        print("construct grandpa<br/>");
        $this->grandPaFkt();
    }

    protected function grandPaFkt(){
        print(">>do Grandpa<br/>");
    }
}

class Pa extends GrandPa
{
    public function __construct()
    {   parent::__construct();
        print("construct Pa <br/>");
    }

    public function paFkt(){
        print(">>do Pa <br>");
    }
}

class Child extends Pa
{
    public function __construct()
    {
        GrandPa::__construct();
        Pa::paFkt();//allright
        //parent::__construct();//whatever you want
        print("construct Child<br/>");
    }

}

$test=new Child();
$test::paFkt();//strict error

因此在扩展类(Child)中可以使用