Run results for: typeof string vs nullish check

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
typeof string	19467.4 Ops/sec
nullish check	18518.6 Ops/sec

HTML Preparation code:

<!--your preparation HTML code goes here-->

Script Preparation code:

var stringArr = Array(10_000).fill(undefined).map((_, index) => `${index + 1}`);
var nullishArr = Array(10_000).fill(undefined).map(() => null);

Tests:

typeof string
const stringResult = stringArr.filter((v) => typeof v === 'string'); const nullishResult = nullishArr.filter((v) => typeof v === 'string');
nullish check
const stringResult = stringArr.filter((v) => v != null); const nullishResult = nullishArr.filter((v) => v != null);