Change relative URL to absolute URL in Javascript

relative_to_absolute.js

// Adapted from https://muaz-khan.blogspot.com/2012/02/absolute-or-relative-url-issues-and.html

function qualifyURL(url) {
    var a = document.createElement('a');
    a.href = url; // set string url
    url = a.href; // get qualified/absolute url
    a.href = null; // no server request
    return url;
}