[CentOS] L9 - what is a value

This code:

var('i') = string;
boolean($i); '<br>';
var('i') = array;
boolean($i); '<br>';

gives:

 > false
 > true

So an empty array gives "true" but an empty string "false".
This is different from L8. Is this intentional? If so, why?

- Jussi