javascript measure time elapsed code example

Example 1: Javascript measure function run time

var startTime = performance.now();

alert('Run some function here');

var endTime = performance.now();
var totalTime=endTime-startTime;// time took to run in milliseconds

alert('Total time:'+totalTime +'ms');

Example 2: get elapsed time javascript date

var startTime, endTime;

function start() {
  startTime = new Date();
};

function end() {
  endTime = new Date();
  var timeDiff = endTime - startTime; //in ms
  // strip the ms
  timeDiff /= 1000;

  // get seconds 
  var seconds = Math.round(timeDiff);
  console.log(seconds + " seconds");
}