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Object cloning> <Magic Methods
Last updated: Fri, 24 Jul 2009

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Final 키워드

PHP 5는 자식 클래스가 메쏘드를 덮어 쓰는 것을 막도록, final 키워드를 지원합니다. 정의시에 final을 앞에 붙이면 됩니다. 클래스 자체를 final로 정의하면 상속할 수 없습니다.

Example #1 Final 메쏘드 예제

<?php
class BaseClass {
   public function 
test() {
       echo 
"BaseClass::test() 호출\n";
   }
   
   final public function 
moreTesting() {
       echo 
"BaseClass::moreTesting() 호출\n";
   }
}

class 
ChildClass extends BaseClass {
   public function 
moreTesting() {
       echo 
"ChildClass::moreTesting() 호출\n";
   }
}
// 결과는 Fatal error: Cannot override final method BaseClass::moreTesting()
?>

Example #2 Final 클래스 예제

<?php
final class BaseClass {
   public function 
test() {
       echo 
"BaseClass::test() 호출\n";
   }

   
// 여기서는 함수의 final 지정 여부는 관계 없습니다.
   
final public function moreTesting() {
       echo 
"BaseClass::moreTesting() 호출\n";
   }
}

class 
ChildClass extends BaseClass {
}
// 결과는 Fatal error: Class ChildClass may not inherit from final class (BaseClass)
?>


Object cloning> <Magic Methods
Last updated: Fri, 24 Jul 2009
 
add a note add a note User Contributed Notes
Final 키워드
Kiam
01-Aug-2009 08:49
The final keyword doesn't change the visibility of a property / method, which is public by default.
jriddy at gmail dot com
18-Jul-2009 06:20
Note for Java developers: the 'final' keyword is not used for class constants in PHP. We use the keyword 'const'.

http://php.net/manual/en/language.oop5.constants.php
sunil dot boodram at gmail dot com
19-Mar-2009 02:54
Using the scope resolution operator, we can easily access constants, static variables, public functions and final functions from Final Classes

Note: even by omitting the "public" keyword from the "nightNews()" method, we can see that the function defaults to public even if prefixed with the keyword final.

<?php
final class news{
 
  const
micCheck = "test1"; // will work
 
static public $promptCheck = "test2"; //will work
 
  //will work
 
public function morningNews(){
    print
'good morning world!';
  }

 
//will work
 
final public function eveningNews(){
    print
'good evening world!';
  }

 
//will work
 
final function nightNews(){
    print
'good night world!';
  }

}

print
news::micCheck; // output: test1
print '<br/>';
print
news::$promptCheck; // output: test2
print '<br/>';
print
news::morningNews(); // output: good morning world!
print '<br/>';
print
news::eveningNews(); // output: good evening world!
print '<br/>';
print
news::nightNews(); // output: good night world!
?>
santoshjoshi2003 at yahoo dot co dot in
05-Dec-2008 07:45
The use of final keyword is just like that occurs in Java
In java final has three uses
    1) prevent class Inheritance
    2) prevent method overriding or redifination of
        method in subclass
    3) and to declare constants
 But the third point seems to be missing from the PHP
 I guess, as i am a java developer Currently gaining competence in PHP
slorenzo at clug dot org dot ve
31-Oct-2007 04:13
<?php
class parentClass {
    public function
someMethod() { }
}
class
childClass extends parentClass {
    public final function
someMethod() { } //override parent function
}

$class = new childClass;
$class->someMethod(); //call the override function in chield class
?>
penartur at yandex dot ru
22-Mar-2007 06:39
Note that you cannot ovverride final methods even if they are defined as private in parent class.
Thus, the following example:
<?php
class parentClass {
    final private function
someMethod() { }
}
class
childClass extends parentClass {
    private function
someMethod() { }
}
?>
dies with error "Fatal error: Cannot override final method parentClass::someMethod() in ***.php on line 7"

Such behaviour looks slight unexpected because in child class we cannot know, which private methods exists in a parent class and vice versa.

So, remember that if you defined a private final method, you cannot place method with the same name in child class.

Object cloning> <Magic Methods
Last updated: Fri, 24 Jul 2009
 
 
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