JSFiddle - React, Tailwind, and code Playground

HTML

<div id="log">

JavaScript

var timeStart = new Date().getTime();

function log(text) {
	var timeNow = new Date().getTime();
	var duration = timeNow - timeStart;
	$("#log").html($("#log").html() + duration + 'ms - ' + text + "<br />")
}


function resolveAfterSecond(x) {
  return new Promise(resolve => {
    setTimeout(() => {
      resolve(Math.pow(2,x));
    }, 100 * x);
  });
}


async function asyncCall(x) {
  log('start fce' + x);
  result = await resolveAfterSecond(1 + x);
  log('hodnota fce' + x + ': ' + result);
  var result = await resolveAfterSecond(10 - x - x);
  log('hodnota fce' + x + ': ' + result);
  log('konec fce' + x);
}

asyncCall(1);
asyncCall(2);
asyncCall(3);
asyncCall(4);