Run results for: Array.map().filter(Boolean) vs Array.flatMap()

Run details:

User agent: Mozilla/5.0 (Linux; Android 12; SM-S901B) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.0.0 Mobile Safari/537.36

Browser: Chrome Mobile 104

Operating system: Android

Device Platform: Mobile

Date tested: 2 years ago

Test name	Executions per second
Array.map().filter(Boolean)	42680.0 Ops/sec
Array.flatMap()	40289.1 Ops/sec

Script Preparation code:

var arr1 = ['', '1231237', '', '', '', '', 'ergre', '', '', '', '', 'asdf1134', '', '', '123'];
var arr2 = ['1231237', '123','1231237', '123','1231237', '', '123sdfsdf','sdfsdf'];

Tests:

Array.map().filter(Boolean)
var result = arr1.map(str => str && arr2.includes(str) && str).filter(Boolean); console.log(result);
Array.flatMap()
var result = arr1.flatMap(str => str && arr2.includes(str) && str ? [str] : []); console.log(result);

Run results for: Array.map().filter(Boolean) vs Array.flatMap()

comparison of filtering out falsy values from an array

Array.map().filter(Boolean)

Array.flatMap()