如何在 JavaScript 中使用键和值列表创建地图

Question

In Java we can create

private map<String, List<String>> map = HashMap<String, ArrayList<String>();

How to create a map with keys and lists of values in JavaScript?

I want to put key as country name and list of values are country states. How to do in JavaScript?

Answer 1

map = {"country1": ["state1", "state2"], "country2": ["state1", "state2"]}

OR dynamically

var map = {};
map["country1"] = ["state1", "state2"];
map["country2"] = ["state1", "state2"];

Answer 2

Here a java and javascript coder.

 //Variable map, contains a instance of Map with a constructor of String and Array of String. let map = new Map([[String.prototype, [String.prototype]]]); //Put values in map. map.set('Country1', ['State1', 'State2']); map.set('Country2', ['State1', 'State2', 'State3']); map.set('CountryN', ['State1', 'State2', 'State3', 'StateN']); //Iterate map and print the content of this. map.forEach((value, key) => { console.log(`Country: ${key} States:[${value}]`); });