Run results for: Get file extension (String v.s. Regex)

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser: Chrome 120

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
String.split	23269.8 Ops/sec
String.split (one-liner, mutation)	23581.4 Ops/sec
Regex.exec	26574.6 Ops/sec

Script Preparation code:

// There are 100 more files
var filePaths = new Array(250).fill('').map(() =>
  (crypto.randomUUID() + crypto.randomUUID())
    .slice(0, 32)
    .replace(/c/g, '.')
    .replace(/(0|9|a)/g, '/'),
);
var fileExt;

Tests:

String.split
for (const path of filePaths) { const args = path.split('.'); fileExt = args[args.length - 1]; }
String.split (one-liner, mutation)
for (const path of filePaths) { fileExt = path.split('.').pop(); }
Regex.exec
for (const path of filePaths) { fileExt = /\.([^\.]+)$/.exec(path)?.[1]; }

Run results for: Get file extension (String v.s. Regex)

Get file extension from path and name

String.split

String.split (one-liner, mutation)

Regex.exec