Preload script without execute

Question

Problem

In order to improve the page performance I need to preload scripts that I will need to run on the bottom page.

I

Answer 1

Why not to try this?

var script = document.createElement('script');
script.src = 'http://path/to/your/script.js';
script.onload = function() {
  // do something here
}

document.head.appendChild(script);

you can use .onload event to control when it is loaded. One caveat is that .onload() doesn't work in IE and you can use this:

script.onreadystatechange = function() {
  if (/^loaded|complete$/i.test(this.readyState)) {
    // loaded
  };
}

Additionally adding scripts via DOM is non-blocking and i believe you can perfectly achieve your goals with this approach.