class error Using $this when not in object context

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开发者_StackOverflow社区 is:'.$this->$x.'--<br>';
}



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

it gives me this error

 Fatal error: Using $this when not in object context 

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.

Your method is static, you can't use $this in static context. You have to use self, but it will trigger a Fatal error because $x is not declared as a static member.

This will work:

class test {

   static protected $x = 'hello world';

   static public function testFunction() {
      echo self::$x;
   }

}

Basically you are using the keyword $this outside the class. There are a lot of syntax errors here:

1 - a } is missing probably in the first function. 2 - i think that not using one of the public, protected, private keyword in a class's function declaration is a mistake. 3 - To call a variable you have to use the $this->var_name syntax, while using a constant you should use the self::cons_name.