saiko saru

In PHP 5.3 you can do Late Static Binding

Through some testing I found that you can overwrite the value of the parents values for both variables and constants by using them statically in the parent class. Here's an example.

php code

class A { static $foo = 'parent var'; const bar = 'parent const'; public function echo_var() { echo static::$foo; } public function echo_const() { echo static::bar; } }

Our class is very generic, we have a static class variable $foo and a constant bar. We also have two supporting functions that will echo out each value. Note that we are using static:: on both and not $this-> or self::

php code

class B extends A { static $foo = 'child var'; const bar = 'child const'; public function test_var() { parent::echo_var(); } public function test_const() { parent::echo_const(); } }

This is our child class where we again define $foo and bar but we set the values differently. Again we have two functions but they're calling the parent functions to echo both values.

The script is set up and executed as such,

php code

$test = new B; $test->test_var(); echo "<br />"; $test->test_const();

The result

quote

child var
child const

as you can see we have successfully modified the variables used in the parent class through the child via Late Static Binding.