Run results for: typeof string vs nullish check

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36

Browser: Chrome 133

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

typeof string

13K/s

nullish check

9K/s

View exact numbers

Test name	Executions per second
✓ typeof string	12,942 Ops/sec
nullish check	8,638 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);