How to run/load a separate javascript file selectively from inside javascript?

Question

I have 3 JavaScript files that I would like to load from an index.html file. I\'m choosing among them by using if statements which I only know how to d

Answer 1

By appending the script to the document.

if(window.innerHeight == 800){
    var script = document.createElement("script");
    script.src = "storybook.js";
    document.getElementsByTagName("head")[0].appendChild(script);
}