When accessing a class array variable member from within a double quoted string it is not interpreted correctly. This is certainly not a critical bug but it would "user friendly" to the developere implement such a thing.  

Example..

<?
class a {
  var $var = array("key" => "value");
}

$inst = a();

echo "$a->var[key]";
?>

Gives us 'Array[key]' instead of what I would expect, which would be 'value'.