JSFiddle - React, Tailwind, and code Playground

by NickU

JavaScript

// create a test document
var str = "";
for (var i=0; i < 10000; i++) {
   str += '<div id="tab' + i + '"></div>';
}
var testDoc = document.createElement('div');
testDoc.innerHTML = str;

// measure the time taken for document.querySelector('#tab1')
var startTime = performance.now();
document.querySelector('#tab1');
var endTime = performance.now();
var querySelectorTime = endTime - startTime;

// measure the time taken for document.getElementById('tab1')
startTime = performance.now();
document.getElementById('tab1');
endTime = performance.now();
var getElementByIdTime = endTime - startTime;

// compare the results to determine which is faster
console.log( querySelectorTime + " "+  getElementByIdTime);
  console.log(parseFloat(querySelectorTime) / parseFloat(getElementByIdTime));