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) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser: Chrome 131

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

set

13.4M/s

object lookup

4.8M/s

indexOf

1.8M/s

includes

1.5M/s

findIndex

913K/s

find

805K/s

View exact numbers

Test name	Executions per second
✓ set	13,396,259 Ops/sec
object lookup	4,820,324 Ops/sec
indexOf	1,778,691 Ops/sec
includes	1,499,617 Ops/sec
findIndex	912,601 Ops/sec
find	804,758 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];}