your right, and you can demonstrate this problem in part by converting the two hashes to lists, splicing them, and then converting them back, if you have any elements that have duplicate names will disappear and the one that came last will get the value and that's already error prone, and then you have the even-list checking and making sure the keys don't become values and vice-verse' by accident -- it can be VERY error prone... its better to just delete and set keys as needed then to do it this way, or merge to hashes, but arrays are like Christmas and hashes are like Easter, if you get what I mean.