No, the map isn't really needed, and might cause confusion, but if it does, I'd bet the @array{@array}=(); idiom isn't going to be understood either.

OP, in both cases above, the idea is to have the numbers in your list to actually be in a hash rather than an array. The map and @array{@array} thing are simply shorthand ways to take your existing array and make it into a hash.

Depending on your actual implementation, you might be better off if you created and added/removed the numbers meant to be within the list, and did so using hash operations instead. Then you wouldn't need the shorthand idioms above.

-Scott