I know LinkedHashMap
has a predictable iteration order (insertion order). Does the Set
returned by LinkedHashMap.keySet()
and the Collection
returned by LinkedHashMap.values()
also maintain this order?
The Map interface provides three collection views, which allow a map's contents to be viewed as a set of keys, collection of values, or set of key-value mappings. The order of a map is defined as the order in which the iterators on the map's collection views return their elements. Some map implementations, like the
TreeMap
class, make specific guarantees as to their order; others, like theHashMap
class, do not.
-- Map
This linked list defines the iteration ordering, which is normally the order in which keys were inserted into the map (insertion-order).
So, yes, keySet()
, values()
, and entrySet()
(the three collection views mentioned) return values in the order the internal linked list uses. And yes, the JavaDoc for Map
and LinkedHashMap
guarantee it.
That is the point of this class, after all.