Run results for: array vs hashmap lookup

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser: Chrome 131

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
array lookup	125548.9 Ops/sec
hash lookup	4953642.5 Ops/sec

Script Preparation code:

function uuid() {
  return ([1e7]+-1e3+-4e3+-8e3+-1e11).replace(/[018]/g, c =>
    (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16)
  );
}
window.versionsArray = Array(100).fill({ type: 'module' }).map(a => ({ ...a, id: uuid(), archiveId: uuid() }))
window.versionsHash = versionsArray.reduce((hash, version) => { 
  if (!hash[version.type]) hash[version.type] = {}
  hash[version.type][version.id] = version.archiveId
  return hash; 
}, {})
window.locateId = versionsArray[70].id
window.locateArchiveId = versionsArray[70].archiveId

Tests:

array lookup
const foundVersionArchiveId = window.versionsArray.find(v => v.type === 'module' && v.id === window.locateId) console.assert(foundVersionArchiveId === window.locateArchiveId)
hash lookup
const foundVersionArchiveId = window.versionsHash.module?.[locateId] console.assert(foundVersionArchiveId === window.locateArchiveId)

Run results for: array vs hashmap lookup

array lookup

hash lookup