variable variables & classes

[podulator]

hi,
i've got a class that mirrors a database table (variable name -> field name) and i was trying to do something thats been simplified below, but it keeps coming back undefined variable whatever i try.....anyone got any ideas if its possible or not...
cheers
mat

<?php

class foo
{

var $arry, $field1, $field2, $field3;

function foo()
{
	$this->arry = array("field1" => "value1", 
			"field2" => "value2", 
			"field3" => "value3");
}	//constructor

function var_var()
{
	$keys = array();
	//count cols
	$num_cols = count($this->arry);

	//get the keys
	$keys = array_keys($this->arry);
	//try and assign
	for ($x = 0; $x < $num_cols; $x++)
	{
		//get column name
		$col_name = $keys[$x];

		//column name is same as variable name
		//so on first pass $this->$$col_name
		//should be the same as
		//$this->field1 etc.....
		$this->$$col_name = $this->arry[$keys[$x]];
	}
}

}	//foo

//test it
$test = new foo();
$test->var_var();

echo $test->field1 . "<br>" . $test->field2 . "<BR>" . $test->field3;

?>

[podulator]

found a workaround, but would like to hear of why it don't work how you'd expect, or any better fixes.....

fix->

		for ($x = 0; $x < $num_cols; $x++)
		{
			//get column name
			$col_name = $keys[$x];

		//make a string out of syntax
		$eval = "\$this->" . $col_name . " = \$this->arry[\"$keys[$x]\"];";
		//eval it
		eval($eval);
	}

cheers
mat