Returns a two-element list consisting of the key and
value for the next element of a hash. With successive
, you can iterate over the entire hash.
Entries are returned in an indeterminate order. When the hash is
entirely read, a null list is returned.
The next call to
will start a new iteration. The iterator can be reset either by reading
all the elements from the hash, or by calling the
scalar context. You must not add elements to the
hash while iterating over it, although you are permitted to use
. In a scalar context,
returns just the key.
There is a single iterator for each hash, shared by all
function calls in
the program. This means that after a
call will start again from the beginning.