Q: Array

Hi group: I've following question: How could I determine whether I have in the array's key integers *and* strings or integers only? i.e. $a = new array('one', 'two', 'three'); // this has only integers (am I wrong?) $b = new array('one' => 'bla', 'two' => 'blabla', 'three' => 'blablabla'); // integers & strings latter could be seen using while(list($k, $v) = each($b)) {...} Result will be 0 (the key) = 'bla' (the value) one (the key of the *same* element) = 'bla' (the *same* value) I hope the question is clear enough and I'll highly appreciate your comments. Thank you Ivo