Run details:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.90 Safari/537.36
Chrome 89
Windows
Desktop
3 years ago
Test name Executions per second
startsWith 1450.8 Ops/sec
.charAt 761.4 Ops/sec
HTML Preparation code:
AخA
 
1
<div></div>
Script Preparation code:
x
 
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;
    }