I like this idea. array_first_key would be nice too
I am probably missing something, but what those would allow to do that
rewind/end+key() doesn't do?
The big thing that it does that end()+key() doesn't do is really what it
doesn't do (update the internal pointer).
end() modifies the array pointer. So if you try this in user-land:
function array_last_key(array $array) {
end($array);
return key($array);
}
It will always force a full copy of the array (at least the hash table).
Implementing this as a core function however would eliminate that one
side-effect...