example

class main
 {
    public $nothing = 'some text';
    public static $variable = "new variable";
    
    public static function doSomething($main) 
    {
      echo "Do something";
      echo "<br>";
      echo $main->nothing;
    }
    
    public function nothing()
    {
      echo "Nothing happend here";
      echo self::$variable;
      echo $this->nothing;
    }
 }
 
 $var = new main();
 $var->nothing();
 main::doSomething($var);