Run results for: Array.find vs map to object then lookup.

For an array of objects, is multiple calls to Array.find performant? Can we improve find performance by first creating a flat array of just the object keys we are looking for, then calling Array.includes?

Go to the benchmark

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:92.0) Gecko/20100101 Firefox/92.0

Browser: Firefox 92

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
find value in the array each time	2349971.8 Ops/sec
lookup the value	5738100.5 Ops/sec

Script Preparation code:

var arr = [{
    num: 'one'
}, {
    num: 'two'
}, {
    num: 'three'
}, {
    num: 'four'
}, {
    num: 'five'
}, {
    num: 'six'
}, {
    num: 'seven'
}, {
    num: 'eight'
}, {
    num: 'nine'
}, {
    num: 'ten'
}];

Tests:

find value in the array each time
var ten = arr.find(n => n.num === 'ten'); var nine = arr.find(n => n.num ==='nine'); var eight = arr.find(n => n.num ==='eight'); var seven = arr.find(n => n.num ==='seven'); var six = arr.find(n => n.num ==='six'); var five = arr.find(n => n.num ==='five'); var four = arr.find(n => n.num ==='four'); var three = arr.find(n => n.num ==='three'); var two = arr.find(n => n.num ==='two'); var one = arr.find(n => n.num ==='one');
lookup the value
var nums = arr.map(o => o.num); var ten = nums.includes('ten'); var nine = nums.includes('nine'); var eight = nums.includes('eight'); var seven = nums.includes('seven'); var six = nums.includes('six'); var five = nums.includes('five'); var four = nums.includes('four'); var three = nums.includes('three'); var two = nums.includes('two'); var one = nums.includes('one');

Run results for: Array.find vs map to object then lookup.

For an array of objects, is multiple calls to Array.find performant? Can we improve find performance by first creating a flat array of just the object keys we are looking for, then calling Array.includes?

find value in the array each time

lookup the value