Learn some es6:map.

Map: Initialize:

Const MAPSIZE = (new Map ()). Size; mapsize:0

Const PAIR1 = [1, ' one '];
Const PAIR2 = [2, ' both '];

Const MAP = new Map ([Pair1, Pair2]); New Map (). Set (... pair1). Set (... pair2);

Whichever is the last set value:

Const PAIR1 = [1, ' one '];
Const PAIR2 = [1, ' Uno '];
Const PAIR3 = [1, ' eins '];
Const PAIR4 = [2, ' both '];
Const MAP = new Map ([Pair1, Pair2, Pair3, PAIR4]); New Map (). Set (... pair3). Set (... pair4);

Let map = new map ();
Const OBJ = {x:1, y:2};
Const KEYS = Object.keys (obj);
Keys.foreach (key = Map.set (key, Obj[key]));

Set, GET, has:

Let map = new map ();
Map.set (' key ', ' value '); Set can be used with OH
Const VALUE = map.get (' key ');

You can use anything to make a key OH:

Let map = new map ();
Const OBJ = {};
Map.set ({}, ' object is key ');

There is also the has method:

Let map = new map ([[' Key ', ' VALUE ']]);
Const HASKEY = Map.has (' key ');

Keys and Values method:

Let map = new map ();
Map.set (1, ' one '). Set (2, ' one ');
Assert.deepequal ([... Map.keys ()], [+]);
Assert.deepequal ([... map.values ()], [' One ', ' both ']);

Learn some es6:map.