java script sleep synchronous

function sleep(milliseconds) {
  var start = new Date().getTime();
  for (var i = 0; i < 1e7; i++) {
    if ((new Date().getTime() - start) > milliseconds){
      break;
    }
  }
}

other version to see https://stackoverflow.com/questions/6484321/sleep-in-javascript-no-settimeout?noredirect=1&lq=1