OrderedMap

A type of Map that maintains the order of iteration according to when entries were set.

Method signature

type OrderedMap<K, V> extends Map<K, V>

The iteration behavior of OrderedMap is the same as native ES6 Map and JavaScript Object.

Note that OrderedMap are more expensive than non-ordered Map and may consume more memory. OrderedMap#set is amortized O(log32 N), but not stable.

Let's look at the following example to see the difference between Map and OrderedMap:

The b key is re-located on the second position.

The b key is still on the third position.

Similar API with Map

OrderedMap has the exact same API as Map. The only new method is OrderedMap.isOrderedMap(maybeOrderedMap) to check if a value is an OrderedMap.

Construction

Creates a new Immutable OrderedMap.

Method signature

OrderedMap<K, V>(collection?: Iterable<[K, V]>): OrderedMap<K, V>
OrderedMap<V>(obj: { [key: PropertyKey]: V }): OrderedMap<PropertyKey, V>

Note: OrderedMap is a factory function and not a class, and does not use the new keyword during construction.

Static Methods

True if the provided value is an OrderedMap.

Method signature

OrderedMap.isOrderedMap(maybeOrderedMap): boolean
;