Run results for: Regex vs 2 x indexOf

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/102.0.0.0 Safari/537.36

Browser: Chrome 102

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Regex	275.2 Ops/sec
2 x indexOf	8694.1 Ops/sec

HTML Preparation code:

<div></div>

Script Preparation code:

window.regex = /^\/start\/\d+\/end/;
window.matchStart = 'start';
window.matchEnd = '/end';
var data = window.data = [];
var TOTAL_STRINGS = window.TOTAL_STRINGS = 100000;

function getRandomInt(max) {
  return Math.floor(Math.random() * max);
}

function makeRandomString(len) {
  var text = "/start/";
  for( var i=0; i < len; i++ ) {
    text += (1 + getRandomInt(9));
  }
  text += "/end";
  return text;
}

while (data.length < TOTAL_STRINGS) {
  data.push(makeRandomString(getRandomInt(8)));
}

Tests:

Regex
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var regex = window.regex; while (x < TOTAL_STRINGS) { const str = data[x]; regex.test(str); x += 1; }
2 x indexOf
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var matchStart = window.matchStart; var matchEnd = window.matchEnd; while (x < TOTAL_STRINGS) { const str = data[x]; (str.indexOf(matchStart) === 1) && (str.indexOf(matchEnd) === str.length - 4); x += 1; }

Run results for: Regex vs 2 x indexOf

Compare if identifying a URL string to be a format of /start/1234/end is faster with regex match or indexOf at start and end

Regex

2 x indexOf