PHP: This and Self

Question

Possible Duplicate:
PHP: self vs this and When to use self over $this

What's the difference between $this and self::

example:

class Object{
   public $property;
   function doSomething(){
        // This
        $something = $this->property;
        // Self
        $something = self::property;
        ...code...
   }
}

exact dupe: http://stackoverflow.com/questions/151969/php-self-vs-this — Trufa, Dec 05 '10 at 22:26

score 3 · Accepted Answer · answered Dec 05 '10 at 22:27

3

$this refers to the instance of the object, while self returns to the class itself. When using static calls, you refer to self because you are not-required to have an instance of a class (i.e. $this).

answered Dec 05 '10 at 22:27

Anthony Forloney

90,123
14
117
115

score 2 · Answer 2 · answered Dec 05 '10 at 22:28

2

$this references the object, in which the code appears, self is the class. You call "usual" methods and properties with $this from within any method and you call static methods and properties with self

class A {
    public static $staticVar = 'abc';
    public $var = 'xyz';
    public function doSomething () {
        echo self::$staticVar;
        echo $this->var;
    }
}

Your "Self"-example is invalid anyway.

answered Dec 05 '10 at 22:28

KingCrunch

128,817
21
151
173

Be careful with `self`. `self` refers to the most recent class in the chain which contains that method. If you have a static `$name` property in both a `ParentClass` and `ChildClass` which hold "Parent" and "Child" respectively, but `showName`, which uses `self::$name`, only exists in `ParentClass` then `$child->showName()` will return `Parent` not `Child`. – AgentConundrum Dec 05 '10 at 23:31
Usually its the prefered behaviour, when `self` really means "the class itself" and not any subclass. Use "Late Static Binding (`static`), which always refers to the called class instead. – KingCrunch Dec 06 '10 at 00:58

score 1 · Answer 3 · edited Feb 16 '18 at 14:13

1

Taken from here

Link: http://www.phpbuilder.com/board/showthread.php?t=10354489:

Use $this to refer to the current object. Use self to refer to the current class. In other words, use $this->member for non-static members, use self::$member for static members.

Answered by John Millikin here

edited Feb 16 '18 at 14:13

Rotimi

4,783
4
18
27

answered Dec 05 '10 at 22:29

Trufa

39,971
43
126
190

PHP: This and Self

3 Answers3