LaravelConf Taiwan 2019 announcement

get_parent_class

(PHP 4, PHP 5, PHP 7)

get_parent_class객체나 클래스의 부모 클래스명을 얻습니다

설명

string get_parent_class ([ mixed $object ] )

객체나 클래스의 부모 클래스명을 획득합니다.

인수

object

확인하는 객체나 클래스명

반환값

object 인스턴스나 클래스명의 부모 클래스명을 반환합니다.

Note:

객체에 부모가 존재하지 않으면 FALSE를 반환합니다.

객체 밖에서 인수 없이 호출하면, FALSE를 반환합니다.

변경점

버전 설명
5.1.0 이전 객체가 밖에서 인수 없이 호출하면, NULL을 반환하고 경고를 발생했습니다.
5.0.0부터 객체 메쏘드에서 호출할 때 object 인수가 선택적이 되었습니다.
4.0.5부터 object가 문자열이면, 그 이름을 가진 클래스의 부모 클래스명을 반환합니다.

예제

Example #1 get_parent_class() 사용하기

<?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();

?>

위 예제의 출력:

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

참고

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User Contributed Notes 6 notes

up
3
falundir at gmail dot com
7 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
matt-php at DONT-SPAM-ME dot bitdifferent dot com
14 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
levu
8 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
yukal dot alexander at gmail dot com
6 months 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
0
radu dot rendec at ines dot ro
15 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.
up
-1
ssb45 at cornell dot edu
11 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.)
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