Benchmark: Array.find vs. Map.get on large datasets

Script Preparation code:

function getRandomElement(id) {
  return {
    id,
    a: Math.random(),
    b: Math.random(),
    c: Math.random(),
  }
}

function getArray(length) {
  const result = [];
  for (let i = 0; i < length; i++) {
    result.push(getRandomElement(i))
  }
  
  return result;
}

function arrayToMap(array) {
  return new Map(array.map(el => [el.id, el]));
}

function getRandomInt(max) {
  return Math.floor(Math.random() * max);
}

array_small = getArray(10000);
array_large = getArray(1000000);

map_small = arrayToMap(array_small);
map_large = arrayToMap(array_large);

Tests:

Array.find, 1 000 000 elements
const target = getRandomInt(999999); array_large.find(el => el.id === target);
Map.get, 1 000 000 elements
const target = getRandomInt(999999); map_large.get(target)
Array to Map + Map.get, 5000 lookups
const map = arrayToMap(array_large); for (let i = 0; i < 5000; i++) { const target = getRandomInt(9999); map.get(target); }
Array.find, 5000 lookups
for (let i = 0; i < 5000; i++) { const target = getRandomInt(9999); array_large.find(el => el.id === target) }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.find, 1 000 000 elements
Map.get, 1 000 000 elements
Array to Map + Map.get, 5000 lookups
Array.find, 5000 lookups

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/605.1.15 (KHTML, like Gecko) Version/18.4 Safari/605.1.15

Browser/OS: Safari 18 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Array.find, 1 000 000 elements	2034.9 Ops/sec
Map.get, 1 000 000 elements	403354560.0 Ops/sec
Array to Map + Map.get, 5000 lookups	17.2 Ops/sec
Array.find, 5000 lookups	40.5 Ops/sec

Related benchmarks:

Array.find vs. Map.get on large datasets (version: 1)

Test the performance of Array.find vs. Map.get, with various array sizes, and with/without conversion from array to map

Comparing performance of: Array.find, 1 000 000 elements vs Map.get, 1 000 000 elements vs Array to Map + Map.get, 5000 lookups vs Array.find, 5000 lookups

Created: one year ago by: Guest

Jump to the latest result

Array.find, 1 000 000 elements

Map.get, 1 000 000 elements

Array to Map + Map.get, 5000 lookups

Array.find, 5000 lookups

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A