Run results for: Regex Memory Consumption

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36

Browser: Chrome 114

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Match	2369624.8 Ops/sec
Exec	2401886.0 Ops/sec
Exec Non-Capturing	2411622.0 Ops/sec
Match non capturing	2409014.8 Ops/sec

Script Preparation code:

var acceptHeader = 'image/*, */*';
var mimes = ['image/avif', 'image/webp'];
var accepts = 'image/avif,image/webp,image/apng,image/svg+xml,image/*,*/*;q=0.8';

Tests:

Match
var regex = new RegExp(`(${mimes.join('|')})(,|;|$)`, 'i'); var match = accepts.match(regex); if (match){ acceptHeader = match[1]; }
Exec
var regex = new RegExp(`(${mimes.join('|')})(?=,|;|$)`, 'i'); var match = regex.exec(accepts); if (match){ acceptHeader = match[0]; }
Exec Non-Capturing
var regex = new RegExp(`(?:${mimes.join('|')})(?=,|;|$)`, 'i'); var match = regex.exec(accepts); if (match){ acceptHeader = match[0]; }
Match non capturing
var regex = new RegExp(`(?:${mimes.join('|')})(?=,|;|$)`, 'i'); var match = accepts.match(regex); if (match){ acceptHeader = match[0]; }

Run results for: Regex Memory Consumption

Match

Exec

Exec Non-Capturing

Match non capturing