Convert an array of objects with a unique id property to a Map

Question

I have an array of objects, where each object has a unique member called id. How do I create a Map where the id if the Map\'s key?

Answer 1

You want to reduce your array into a map:

const arr = [{id:1},{id:2},{id:2}];

const map = arr.reduce((acc, item) => acc.set(item.id, item), new Map());

console.log(map.get(1));

Here is a JSPref against using map and forEach.

In Chrome v53 reduce is fastest, then forEach with map being the slowest.