Run results for: startsWith vs include vs substring vs Array.from

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:146.0) Gecko/20100101 Firefox/146.0

Browser: Firefox 146

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 7 months ago

JS includes

7K/s

JS startsWith

6K/s

JS substring

3K/s

Array.from

107/s

View exact numbers

Test name	Executions per second
✓ JS includes	6,617 Ops/sec
JS startsWith	6,011 Ops/sec
JS substring	3,304 Ops/sec
Array.from	107 Ops/sec

Script Preparation code:

window.prefix = "!";
const possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

function getRandomInt(max) {
  return Math.floor(Math.random() * max);
}

function makeRandomString(len) {
  var text = "";
  for( var i=0; i < len; i++ ) {
    text += possible.charAt(getRandomInt(possible.length));
  }
  return text;
}

window.allStrings = [];
for (let i = 0; i < 1000; i++) {
	allStrings.push(window.prefix + makeRandomString(1000));
	allStrings.push(makeRandomString(1000));
}

Tests:

JS startsWith
window.allStrings.forEach(s => { s.startsWith(window.prefix); })
JS includes
window.allStrings.forEach(s => { s.includes(window.prefix); })
JS substring
window.allStrings.forEach(s => { s.substring(0, window.prefix.length) === window.prefix; })
Array.from
window.allStrings.forEach(s => { Array.from(s)[0] === window.prefix; })