Load multiple scripts asynchronously in javascript

async-scripts.ts

loadScripts([
  'https://cdnjs.cloudflare.com/ajax/libs/tinycolor/1.4.1/tinycolor.min.js',
  'https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js'
], () => {
  console.log('Scripts loaded');
  let color = tinycolor('hsl(207, 95%, 44%)');
  console.log(color);
  $('body').css('background-color', color.toHexString());
});

function loadScript(url: string, callback: Function) {
  let script = document.createElement('script');
  script.type = 'text/javascript';
  script.src = url;
  script.onreadystatechange = callback;
  script.onload = callback;
  document.head.appendChild(script);
}

function loadScripts(urls: string[], callback: Function) {
  let loadedCount = 0;
  let multiCallback = () => {
    loadedCount++;
    if (loadedCount >= urls.length) {
      callback.call(this, arguments);
    }
  };
  for (let url of urls) {
    loadScript(url, multiCallback);
  }
}