dynamic class property $$value in php

Question

How can i reference a class property knowing only a string?

class Foo
{
    public $bar;

    public function TestFoobar()
    {
        $this->foobar('bar');
    }

    public function foobar($string)
    {
         echo $this->$$string; //doesn't work
    }
}

what is the correct way to eval the string?

Answer 1

You only need to use one $ when referencing an object's member variable using a string variable.

echo $this->$string;