HH\KeyedContainer
KeyedContainer
allows you to do (foreach $value as $k => $v, $value[$key])
and is an
interface used by both Hack arrays (vec/dict/keyset) and Hack collections (Vector/Map/Set)
If you need to iterate over an array / collection with keys, use KeyedContainer; otherwise, use Container.
Without iterating, you can access keys directly: $keyed_container[$key]
.
Guides
Interface Synopsis
namespace HH;
interface KeyedContainer implements Container<Tv>, KeyedTraversable<Tk, Tv> {...}