Run results for: String in Array: Set vs Object lookup vs IndexOf vs includes vs findIndex vs find v2

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/119.0

Browser: Firefox 119

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
indexOf	751540.1 Ops/sec
includes	802099.4 Ops/sec
find	551915.9 Ops/sec
findIndex	553021.4 Ops/sec
set	783347.8 Ops/sec
object lookup	2581709.0 Ops/sec

Script Preparation code:

var arr = [];
var i = 0;
while (i <= 10) arr[i] = ('' + i++);
var testSet = new Set(arr);
var testObj = {};
for (const a of arr) {
  testObj[a] = true;
}


var randomKeys = [];
i = 0;
while (i <= 50) {
 randomKeys.push(''+Math.round(Math.random(50000) + 5000));
  i++;
}

Tests:

indexOf
for (const key of randomKeys) {const index = arr.indexOf(key);}
includes
for (const key of randomKeys) {const index = arr.includes(key);}
find
for (const key of randomKeys) {const index = arr.find(item => item == key);}
findIndex
for (const key of randomKeys) {const index = arr.findIndex(item => item == key);}
set
for (const key of randomKeys) {const index = testSet.has(key);}
object lookup
for (const key of randomKeys) {const index = testObj[key];}

Run results for: String in Array: Set vs Object lookup vs IndexOf vs includes vs findIndex vs find v2

indexOf

includes

find

findIndex

set

object lookup