Question

this code takes a url as input, but I’m not sure what it does or what’s the benefit of doing this

var hashPos = url.lastIndexOf ( '#' );
return url.substring( hashPos + 1 );

Answer 1

It fetches the hash value off a URL:

So, if the URL is this: http://something.com/foo#xyz, it gets the xyz

If there is no hash mark in the URL, this code returns the entire URL (which may not be the desired outcome).

This is probably a safer variation that returns an empty string, when there is no hash value:

var hashPos = url.lastIndexOf ( '#' );
if (hashPos != -1) {
    return url.substring( hashPos + 1 );
} else {
    return("");
}