class error当不在对象上下文中时使用$ this

Question

I have the following class and its not accepting $this keyword in the method. can someone guid

<?php
class test {

    function __construct($x, $y, $z){

        $this->$x = $x;


        $this->testFunction();





public static function testFunction(){



    print '<br> here it is:'.$this->$x.'--<br>';
}



//========================================================================================================================
}
?>

it gives me this error

 Fatal error: Using $this when not in object context 

Answer 1

In a static function, you need to use self:

print '<br> here it is:'.self::$x.'--<br>';

$this refers to an object instance, which does not exist in a static context.

That said, in a static context, the constructor will never have been called so $x will always be empty. I'm not sure whether public static function is really what you want here.

Edit: Additionally, as @netcoder points out, $x needs to be declared a static member as well.