Benchmark: .startsWith vs .charAt for single character

HTML Preparation code:

<div></div>

Script Preparation code:

var data = window.data = [];
const possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
var TOTAL_STRINGS = window.TOTAL_STRINGS = 100000;

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;
}

while (data.length < TOTAL_STRINGS) {
  data.push(makeRandomString(getRandomInt(20)));
}

Tests:

startsWith
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]; str.startsWith("A"); x += 1; }
.charAt
var x = 0; var TOTAL_STRINGS = window.TOTAL_STRINGS; var data = window.data; var match = window.match; while (x < TOTAL_STRINGS) { const str = data[x]; str.charAt(0) === 'A'; x += 1; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
startsWith
.charAt

Fastest: N/A

Slowest: N/A

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Latest run results:

Run details: (Test run date: 15 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:125.0) Gecko/20100101 Firefox/125.0

Browser/OS: Firefox 125 on Windows

View result in a separate tab

Test name	Executions per second
startsWith	23492.0 Ops/sec
.charAt	23315.6 Ops/sec

.startsWith vs .charAt for single character (version: 0)

Testing some things

Comparing performance of: startsWith vs .charAt

Created: 5 years ago by: Guest

Jump to the latest result

startsWith

.charAt

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A