PHP combine $this variable

Question

How to combine two variables to obtain / create new variable?

public $show_diary = 'my';

private my_diary(){
  return 1;
}

public view_diary(){
 return ${"this->"}.$this->show_diary.{"_diary()"}; // 1
 return $this->.{"$this->show_diary"}._diary() // 2
}

both return nothing.

Answer 1

Your class should be like following:

class Test
{
    public $show_diary;

    function __construct()
    {
        $this->show_diary = "my";
    }
    private function my_diary(){
      return 707;
    }

    public function view_diary(){
        echo $this->{$this->show_diary."_diary"}(); // 707
    }
}