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如何让PHP类构造函数调用其父类的父级构造函数

constructor inheritance oop class php

180

Paulo · 技术社区 · 17 年前

我需要在PHP中有一个类构造函数调用其父类的亲本 (祖父母?)不调用父构造函数的构造函数。

// 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臭的方法,但尽管如此,我很好奇这是否可行。

编辑

我想我应该公布所选答案的理由。原因是,它是对希望在保留所有值的同时调用“祖父母的”构造函数的问题的最优雅的解决方案。这当然不是最好的方法,也不友好,但这不是问题所在。

对于以后遇到这个问题的人- 请找到另一个解决方案 . 我找到了一种更好的方法,它不会破坏课堂结构。你也应该这样。

15 回复 | 直到 9 年前

129

Corey Ballou 17 年前

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

    }

}

class Papa extends Grandpa
{
    public function __construct($bypass = false)
    {
        // only perform actions inside if not bypassing
        if (!$bypass) {

        }
        // call Grandpa's constructor
        parent::__construct();
    }
}

class Kiddo extends Papa
{
    public function __construct()
    {
        $bypassPapa = true;
        parent::__construct($bypassPapa);
    }
}

too much php 17 年前

Grandpa::__construct() Papa __construct() Kiddo

Alain57 14 年前

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 not a bug, it works that way in php
        Grandpa::__construct();
    }
}

j0k gauthamp 13 年前

MitMaro 17 年前

<?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";

Aleksei Akireikin 11 年前

Reflection

<?php
class Grandpa 
{
    public function __construct()
    {
        echo "Grandpa's constructor called\n";
    }

}

class Papa extends Grandpa
{
    public function __construct()
    {
        echo "Papa's constructor called\n";

        // call Grandpa's constructor
        parent::__construct();
    }
}

class Kiddo extends Papa
{
    public function __construct()
    {
        echo "Kiddo's constructor called\n";

        $reflectionMethod = new ReflectionMethod(get_parent_class(get_parent_class($this)), '__construct');
        $reflectionMethod->invoke($this);
    }
}

$kiddo = new Kiddo();
$papa = new Papa();

Fishdrowned Yajo 13 年前

class Grandpa 
{
    public function __construct()
    {
        echo 'Grandpa<br/>';
    }

}

class Papa extends Grandpa
{
    public function __construct()
    {
        echo 'Papa<br/>';
        parent::__construct();
    }
}

class Kiddo extends Papa
{
    public function __construct()
    {
        // THIS IS WHERE I NEED TO CALL GRANDPA'S
        // CONSTRUCTOR AND NOT PAPA'S
        echo 'Kiddo<br/>';
        Grandpa::__construct();
    }
}

$instance = new Kiddo;

https://bugs.php.net/bug.php?id=42016

class Grandpa 
{
    public function __construct()
    {
        echo 'Grandpa<br/>';
        Kiddo::hello();
    }

}

class Papa extends Grandpa
{
    public function __construct()
    {
        echo 'Papa<br/>';
        parent::__construct();
    }
}

class Kiddo extends Papa
{
    public function __construct()
    {
        // THIS IS WHERE I NEED TO CALL GRANDPA'S
        // CONSTRUCTOR AND NOT PAPA'S
        echo 'Kiddo<br/>';
        Grandpa::__construct();
    }

    public function hello()
    {
        echo 'Hello<br/>';
    }
}

$instance = new Kiddo;

$papa = new Papa;

if ($this instanceof Kiddo) Kiddo::hello();

mway 16 年前

class Foo {
    var $f = 'bad (Foo)';

    function __construct() {
        $this->f = 'Good!';
    }
}

class Bar extends Foo {
    var $f = 'bad (Bar)';
}

class FooBar extends Bar {
    var $f = 'bad (FooBar)';

    function __construct() {
        # FooBar constructor logic here
        call_user_func(array(get_parent_class(get_parent_class($this)), '__construct'));
    }
}

$foo = new FooBar();
echo $foo->f; #=> 'Good!'

Xorax 13 年前

officialy supported

// main class that everything inherits
class Grandpa 
{
    public function __construct()
    {
        echo $this->one; // will print 1
        echo $this->two; // error cannot access protected property
    }

}

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

class Kiddo extends Papa
{
    public $one = 1;
    protected $two = 2;
    public function __construct()
    {
        Grandpa::__construct();
    }
}

new Kiddo();

Hauke 10 年前

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

parent::paFkt();

Pa::paFkt();

$test::paFkt();

lepe 12 年前

protected function call2Granpa() {
     return parent::__construct();
}

parent::call2Granpa();

Anand P 12 年前

<?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();
?>

luchaninov pEteR 13 年前

// main class that everything inherits
class Grandpa 
{
    public function __construct()
    {
        $this->___construct();
    }

    protected function ___construct()
    {
        // grandpa's logic
    }

}

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

class Kiddo extends Papa
{
    public function __construct()
    {
        parent::___construct();
    }
}

Crazy Alien 11 年前

    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();
    }
}

-1

lala977 9 年前

parent::parent::__construct();