Run results for: JavaScript Checking That A String Starts With A Value - Value Is **NOT** Found - Benchmarks - Playground

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36

Browser: Chrome 122

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Value Not Found - string.indexOf method

3K/s

Value Not Found - string.match method

122/s

Value Not Found - string.startsWith method

106/s

Value Not Found - string.search method

43/s

View exact numbers

Test name	Executions per second
✓ Value Not Found - string.indexOf method	3,024 Ops/sec
Value Not Found - string.match method	122 Ops/sec
Value Not Found - string.startsWith method	106 Ops/sec
Value Not Found - string.search method	43 Ops/sec

HTML Preparation code:

<div></div>

Script Preparation code:

const iterationNum = 250000;
const possible = "ACDEFGHIJKLMNOPQRSTUVWXYZ0123456789acdefghijklmnopqrstuvwxyz"; // The letter B (and b) is removed
const possibleLen = possible.length;

function getRandomIntInclusive(max, min = 1) {
  const minCeiled = Math.ceil(min);
  const maxFloored = Math.floor(max);
  return Math.floor(Math.random() * (maxFloored - minCeiled + 1) + minCeiled); // The maximum is inclusive and the minimum is inclusive
}

function makeRandomString(len, defaultWord = '') {
  let text = defaultWord;
  for(let i = 0; i < len; i++) {
    text += possible.charAt(getRandomIntInclusive(possibleLen, 0));
  }
  return text + defaultWord;
}

const testWord = window.testWord = makeRandomString(getRandomIntInclusive(10)) + 'Bb'; // B or b shouldn't be in any generated word
const allStrings = window.allStrings = new Array(iterationNum);
const numberOfStrings = window.numberOfStrings = iterationNum;

for(let i = 0; i < numberOfStrings; i++) {
    allStrings[i] = makeRandomString(getRandomIntInclusive(20), testWord);
}

Tests:

Value Not Found - string.startsWith method
let x = 0; const numberOfStrings = window.numberOfStrings; const allStrings = window.allStrings; const testWord = window.testWord; while (x < numberOfStrings) { const str = allStrings[x]; str.startsWith(testWord); x += 1; }
Value Not Found - string.indexOf method
let x = 0; const numberOfStrings = window.numberOfStrings; const allStrings = window.allStrings; const testWord = window.testWord; const testWordLen = testWord.length; while (x < numberOfStrings) { const str = allStrings[x]; str.indexOf(testWord) === 0; x += 1; }
Value Not Found - string.search method
let x = 0; const numberOfStrings = window.numberOfStrings; const allStrings = window.allStrings; const testWord = window.testWord; const testWordLen = testWord.length; while (x < numberOfStrings) { const str = allStrings[x]; str.search(testWord) === 0; x += 1; }
Value Not Found - string.match method
let x = 0; const numberOfStrings = window.numberOfStrings; const allStrings = window.allStrings; const testWord = window.testWord; const testWordRegExp = new RegExp(`^${testWord}`); while (x < numberOfStrings) { const str = allStrings[x]; str.match(testWordRegExp); x += 1; }