keys()
The keys(%arrayname) lists all the key names in a specified
associative array. The answer is returned as an ordinary index array.
E.g.
@names = keys(%lookup);
values() This operator returns the values of the specified associative array.
E.g.
@codes = keys(%lookup);
delete deletes an associated key and value by key reference, e.g.
# scrub adam from code list
delete $lookup("adam");