Javascript Map Key Value. Map is a collection of elements where each element is stored as a Key value pair. It is not invoked for keys that have been deleted.
Before we had Maps we. Mapdeletekey removes the value by the key returns true if key existed at the moment of the call otherwise false. It returns the key value pair in the same order as inserted.
Map object can hold both objects and primitive values as either key or value.
It returns the key value pair in the same order as inserted. The keys and values in the map collection may be of any type and if a value is added to the map collection using a key which already exists in the collection then the new value replaces the old value. You should either iterate with forin or Objectkeys like this. If you try to get a non-existing key using get out of a map it will return undefined.
