Run results for: indexOf vs push

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Safari/537.36

Browser: Chrome 109

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
filter index	209129.9 Ops/sec
push	106504.8 Ops/sec

Tests:

filter index
let strArray = [ "q", "w", "w", "w", "e", "i", "u", "r"]; let findDuplicates = arr => arr.filter((item, index) => arr.indexOf(item) !== index); console.log(findDuplicates(strArray));
push
const strArray = [ "q", "w", "w", "e", "i", "u", "r", "q"]; const alreadySeen = {}; strArray.forEach(str => alreadySeen[str] ? console.log(str) : alreadySeen[str] = true);