略微加速

PHP官方手册 - 互联网笔记

PHP - Manual: get_parent_class

2024-04-24

get_parent_class

(PHP 4, PHP 5, PHP 7, PHP 8)

get_parent_class — 返回对象或类的父类名

说明

get_parent_class(mixed $obj = ?): string

如果 obj 是对象，则返回对象实例 obj 所属类的父类名。

如果 obj 是字符串，则返回以此字符串为名的类的父类名。此功能是在 PHP 4.0.5 中增加的。

注意:

自 PHP 5 起，如果在对象的方法内调用，则 obj 为可选项。

示例 #1 使用 get_parent_class()

<?php

class dad {
    function dad()
    {
    // implements some logic
    }
}

class child extends dad {
    function child()
    {
        echo "I'm " , get_parent_class($this) , "'s son\n";
    }
}

class child2 extends dad {
    function child2()
    {
        echo "I'm " , get_parent_class('child2') , "'s son too\n";
    }
}

$foo = new child();
$bar = new child2();

?>

以上例程会输出：

I'm dad's son
I'm dad's son too

参见 get_class() 和 is_subclass_of()。

参数

object

The tested object or class name

返回值

Returns the name of the parent class of the class of which object is an instance or the name.

注意:

If the object does not have a parent or the class given does not exist false will be returned.

If called without parameter outside object, this function returns false.

更新日志

版本 说明
Before 5.1.0 If called without parameter outside object, this function would have returned null with a warning.
Since 5.0.0 The object parameter is optional if called from the object's method.
Since 4.0.5 If object is a string, returns the name of the parent class of the class with that name.

范例

示例 #2 Using get_parent_class()

<?php

class dad {
    function dad()
    {
    // implements some logic
    }
}

class child extends dad {
    function child()
    {
        echo "I'm " , get_parent_class($this) , "'s son\n";
    }
}

class child2 extends dad {
    function child2()
    {
        echo "I'm " , get_parent_class('child2') , "'s son too\n";
    }
}

$foo = new child();
$bar = new child2();

?>

以上例程会输出：

I'm dad's son
I'm dad's son too

参见

add a noteadd a note

User Contributed Notes 7 notes

up
6
yukal dot alexander at gmail dot com
3 years ago
An output of the entire inheritance chain using closures, recursion, and OOP

class ParentClass {
    public static function getChain() {
        $chain = null;
        return $function = function($className='') use (& $chain, & $function) {
            if (empty($className))
                $className = static::class;

            if (empty($chain))
                $chain = $className;

            $parent = get_parent_class($className);

            if ($parent !== false) {
                $chain .= " > {$parent}";
                return $function($parent);
            }

            return $chain;
        };
    }
}

class Child extends ParentClass {}
class SubChild extends Child {}
class Sub2 extends SubChild {}
class Sub3 extends Sub2 {}
class Sub4 extends Sub3 {}
class Sub5 extends Sub4 {}
class Sub6 extends Sub5 {}
class Sub7 extends Sub6 {}

printf("%s\n", Sub7::getChain()());

$getChain = Sub7::getChain();
printf("%s\n", $getChain('Sub3'));

Output is:
Sub7 > Sub6 > Sub5 > Sub4 > Sub3 > Sub2 > SubChild > Child > ParentClass
Sub3 > Sub2 > SubChild > Child > ParentClass
up
2
falundir at gmail dot com
10 years ago
You can use this function to find common parent of multiple objects or classes.

<?php
/**
* Returns name of the first (in class hierarchy) common parent class of all provided objects or classes.
* Returns FALSE when common class is not found.
*
* @param mixed $objects Array that can contain objects or class names.
* @return mixed
*/
function get_first_common_parent($objects) {
    $common_ancestors = null;
    foreach($objects as $object) {
        if (is_object($object)) {
            $class_name = get_class($object);
        } else {
            $class_name = $object;
        }
       
        $parent_class_names = array();
        $parent_class_name = $class_name;
        do {
            $parent_class_names[] = $parent_class_name;
        } while($parent_class_name = get_parent_class($parent_class_name));
       
        if ($common_ancestors === null) {
            $common_ancestors = $parent_class_names;
        } else {
            $common_ancestors = array_intersect($common_ancestors, $parent_class_names);
        }
    }
   
    return reset($common_ancestors);
}
?>

Example:

<?php
class A {
}

    class B extends A {
    }
   
        class D extends B {
        }
       
        class E extends B {
        }

    class C extends A {
    }

        class F extends C {
        }
   
            class G extends F {
            }

class H {
}

//returns "A"
get_first_common_parent(array('G', 'E'));

//returns "F"
get_first_common_parent(array(new G(), 'F'));

//returns false (no common parent)
get_first_common_parent(array('C', 'H'));

//returns false (non-existent class provided)
get_first_common_parent(array(new B(), 'X'));
?>
up
2
levu
11 years ago
I wrote a simple function doing the reverse thing: get the children:

<?php
function get_child($instance, $classname) {
    $class = $classname;
    $t = get_class($instance);
    while (($p = get_parent_class($t)) !== false) {
        if ($p == $class) {
            return $t;
        }
        $t = $p;
    }
    return false;
}

abstract class A {
    function someFunction() {
        return get_child($this, __CLASS__);
    }
}

class B extends A {

}

class C extends B {

}

$c = new C();
echo $c->someFunction(); //displays B

?>
up
1
matt-php at DONT-SPAM-ME dot bitdifferent dot com
17 years ago
PHP (4 at least, dunno about 5) stores classnames in lower case, so:

<?PHP

class Foo
{
}

class Bar extends Foo
{
}

echo get_parent_class('Bar');

echo "\n";

echo get_parent_class('bar');

?>

will output:

foo
foo
up
1
jake at qzdesign dot co dot uk
2 years ago
Note that from PHP 5.5 you can also use `parent::class` from within a method, e.g.

<?php
    function child()
    {
        echo "I'm ", parent::class, "'s son\n";
    }
?>

Looks a bit tidier and technically probably more optimal, as it avoids a function call lookup.
up
0
ssb45 at cornell dot edu
14 years ago
"'If called without parameter outside object' What on earth does that mean?"

There are two places this could be called:
1. From within a member function of an object.  In this case, it may be called with no parameters and will return the parent class of the object owning the member function.  (If the parameter is included, then it will return the parent class of the specified class as normal.)

2. From outside an object (i.e., global or function scope).  In this case, PHP doesn't know what class you're talking about if you don't include a parameter, so it returns FALSE.  (But, of course, it works if you specify the class with the parameter.)
up
-1
radu dot rendec at ines dot ro
18 years ago
If the argument obj is a string and the class is not defined, then the function returns FALSE.

If the argument obj is an object created from a class with no ancestors (or a string representing a class with no ancestors), then the function returns FALSE.
add a noteadd a note

官方地址：https://www.php.net/manual/en/function.get-parent-class.php

有任何技术问题请点击这里 网站运营推广招聘
IT PHP 编程语言 Linux 科技 开发编程 Elasticsearch HTML/CSS/XML 网络 JAVA NoSQL C/C++ 面试 Golang 数据库 Git 算法 正则表达式 操作系统 Redis 互联网 MySql JavaScript 运维 软件 架构设计 Mac OS TCP/IP 国际 Excel Vim Windows Socket Oracle VR MongoDB 运营 Python MemCache 商业 硬件 电子 设计 nginx 娱乐 摄影 游戏 WordPress HTTP 团建 数码电器
冷却塔厂家 广告
中文GPT4.0无需注册 广告
php7 安装fileinfo扩展 preg_split — 通过一个正则表达式分隔字符串 [PHP] inet_pton/inet_ntop IP地址转换函数 php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题 PHPMailer设置utf8 PHPMailer字符集CharSet 如何在Composer中为GitLab实例设置访问令牌 array_multisort() 多字段排序 laravel框架查看sql语句方式 [原创]诡异的php-fpm超时问题 PHP获取指定函数定义在哪个文件中及行号 利用php soap实现web service php设置cookie为httponly防止xss攻击 PHP5 扩展SOAP 调用 webservice PHP-FPM进程数的设定 利用PHP SOAP实现WEB SERVICE PHP7添加redis扩展 纯php实现DES以及TripleDES加密算法 Composer的Packagist资源 PHPstorm 里面Terminal 不能使用 esc键吗退出编辑模式吗 php扩展开发
联系我们 半月雨文化 可降解耗材网 蓝云环保 生活百科 台州治疗白癜风医院 工程造价 78免费小説 上海网站seo优化 DDnovel 96小説 seo查询
北京半月雨文化科技有限公司.版权所有 京ICP备12026184号-3