Run results for: Filter Boolean vs. Custom Function

Run details:

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:109.0) Gecko/20100101 Firefox/113.0

Browser: Firefox 113

Operating system: Windows 7

Device Platform: Desktop

Date tested: 11 months ago

Test name	Executions per second
filter(Boolean)	2645.0 Ops/sec
filter function	3859.6 Ops/sec

Script Preparation code:

var arr = Array.from({length: 10000}, () => Math.random() > 0.5 ? null : "foo");

Tests:

filter(Boolean)
const numTruthy = arr.filter(Boolean).length; console.log(numTruthy);
filter function
const numTruthy = arr.filter(x => !!x).length; console.log(numTruthy);