Benchmark: Array.includes() vs Set.has() for small Arrays invoked multiple times

Script Preparation code:

function getArray(length) {
  const result = [];
  for (let i = 0; i < length; i++) {
    result.push(i + 'abc'); // In case the browser does some sort of optimization for arrays with only integers ¯\_(ツ)_/¯
  }
  return result;
}

function getRandomTargetElement(arrayLength) {
  const index = Math.floor(Math.random() * arrayLength);
  return index + 'abc';
}


array_small = getArray(20);

set_small = new Set(array_small);

Tests:

Array.includes, 20 elements
array_small.includes(getRandomTargetElement(20));
Set.has, 20 elements
set_small.has(getRandomTargetElement(20))
Array to Set + Set.has x 1000, 20 elements
const set = new Set(array_small); for (let i = 0; i < 1000; i++) { const target = getRandomTargetElement(20); set.has(target) }
Array.includes x 1000, 20 elements
for (let i = 0; i < 1000; i++) { const target = getRandomTargetElement(20); array_small.includes(target) }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.includes, 20 elements
Set.has, 20 elements
Array to Set + Set.has x 1000, 20 elements
Array.includes x 1000, 20 elements

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36

Browser/OS: Chrome 133 on Mac OS X 10.15.7

View result in a separate tab

Set.has, 20 elements

35.7M/s

Array.includes, 20 elements

18.5M/s

Array to Set + Set.has x 1000, 20 elements

41K/s

Array.includes x 1000, 20 elements

21K/s

View exact numbers

Test name	Executions per second
✓ Set.has, 20 elements	35,651,828 Ops/sec
Array.includes, 20 elements	18,464,856 Ops/sec
Array to Set + Set.has x 1000, 20 elements	41,122 Ops/sec
Array.includes x 1000, 20 elements	20,634 Ops/sec

Array.includes() vs Set.has() for small Arrays invoked multiple times (version: 1)

Comparing performance of: `Array.includes, 20 elements vs Set.has, 20 elements vs Array to Set + Set.has x 1000, 20 elements vs Array.includes x 1000, 20 elements`

Created: one year ago by: Guest

Go to the latest result

Array.includes, 20 elements

Set.has, 20 elements

Array to Set + Set.has x 1000, 20 elements

Array.includes x 1000, 20 elements

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Array.includes() vs Set.has() for small Arrays invoked multiple times (version: 1)

Comparing performance of: Array.includes, 20 elements vs Set.has, 20 elements vs Array to Set + Set.has x 1000, 20 elements vs Array.includes x 1000, 20 elements

Created: one year ago by: Guest

Go to the latest result

Array.includes, 20 elements

Set.has, 20 elements

Array to Set + Set.has x 1000, 20 elements

Array.includes x 1000, 20 elements

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Related benchmarks

Comparing performance of: `Array.includes, 20 elements vs Set.has, 20 elements vs Array to Set + Set.has x 1000, 20 elements vs Array.includes x 1000, 20 elements`