I can use the instance variable as [dynamic variable function](http://php.net/manual/en/functions.variable-functions.php) inside the same class's method. But only declaring it locally to another variable inside the method. I can't use it like: "*$this->$this->functionName*". What i mean is:

This works: 
TheClass.php

```
<?PHP
   class TheClass{
      public $functionName;

      function setFunctionName($name){
         $this->functionName = $name;
      }

      function processClass(){
         $tempFunctionName = $this->functionName;
         $this->$tempFunctionName();
      }

      function testFunction(){
      echo "this works";
      }
   }
?>

```

main.php

```
<?PHP
include "TheClass.php";
$theClass = new TheClass();

$theClass->setFunctionName('testFunction');
$theClass->processClass();
?>

```

But i can't use it all in one line like this way:

```
function processClass(){
   $this->$this->functionName();
}

```

Is there a way (out of using [call\_user\_func](http://php.net/manual/en/function.call-user-func.php) ) to use it this way or have i to use it with locally setting it.