Description:
------------
Consider 2 classes

class user
class reports extends user

user stores public variables such as public $username using $this->username;

I want to be able to dynamically say in class reports

echo $this->$field where $field = "username", "first_name" etc.

Reproduce code:
---------------
---
From manual page: http://www.php.net/language.variables.variable
---
class user {
public $username;

function username() { 
//queries from db table and gets
$this->username = $username; //from table
}

class reports extends user {
function userInfo($gid,$arrFieldstoReport) {
parent::__construct($gid)
//loop through $arrFieldstoReport
echo "username = " . $this->arrFieldstoReport[$i]
}
}

Expected result:
----------------
This should echo the following if $arrFieldstoReport[$i] = "username"

echo $this->arrFieldstoReport[$i];
//should echo 
username = testusername (or any other username depending on what group_id it is on)