create javascript map with two keys

Question

I would like to create a map in JavaScript with two keys or need to know if there is a better solution. I need to know if key1 is part of the collection and if so get data1 and in another case I need to know if a value of type key2 is part of the collection and get its data. How do you do this in JavaScript?

Example:

const contacts = new Map();
contacts.set('key_person',  {phone: "617-555-4321", address: "321 S 2nd St"});

const contacts2 = new Map();
contacts.set('key_city',  {phone: "617-555-4321", address: "321 S 2nd St"});

At the moment I have maps with redundant information in order to get data by key_person and key_city. I want a joint map where I can filter for both keys at a time. Thanks you

Why don't you use 1 object containing all the information? You could then find your object by any of your object's properties — Babis.amas
– Babis.amas, Commented Dec 9, 2021 at 19:01

BoltKey · Accepted Answer · 2021-12-09 19:38:37Z

2

I would create a simple class with such functionality.

class DoubleKeyedMap {
  constructor() {
    this.data1 = new Map();
    this.data2 = new Map();
  }
  set(key1, key2, value) {
    this.data1.set(key1, value);
    this.data2.set(key2, value);
  }
  get(key) {
    if (this.data1.get(key) !== undefined) {
      return this.data1.get(key);
    }
    return this.data2.get(key);
  }
  // TODO: clear, delete, has, keys, values, entries
}

const contacts = new DoubleKeyedMap();
contacts.set("key-person", "key-city", {phone: "617-555-4321", address: "321 S 2nd St"});
contacts.get("key-city");

answered Dec 9, 2021 at 19:38

BoltKey

2,2781 gold badge16 silver badges30 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Boellner Over a year ago

thanks, another question: how would iterate through it? for (var key in this.mapping) { and mapping is an array

Collectives™ on Stack Overflow

create javascript map with two keys

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related