PHP Self vs this?



Hi, this sounds very embarrassing but i've been using too much $this->field keyword for so long i can't remember what's the difference between "php $this" and "php self".

does php "self" has any special functionality besides being called differently? surely there must've been some purpose.

example,
instead of $this->GetMyName(), it becomes self::GetMyName();

?

2 years 3 days ago   Tags:


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. (Reference: http://www.phpbuilder.com/board/showthread.php?t=10354489)

Examples:

Here is an example of correct usage of $this and self for non-static and static member variables:


<?php
class X {
    private $non_static_member = 1;
    private static $static_member = 2;

    function __construct() {
        echo $this->non_static_member . ' '
           . self::$static_member;
    }
}

new X();
?> 

Here is an example of polymorphism with $this for member functions:


<?php
class X {
    function foo() {
        echo 'X::foo()';
    }

    function bar() {
        $this->foo();
    }
}

class Y extends X {
    function foo() {
        echo 'Y::foo()';
    }
}

$x = new Y();
$x->bar();
?>