option-filter | Adds a .filter method to Option T | Widget library

I'm using jQuery getJSON to retrieve posts from the WP API v2.

I have some input fields which I want to be clickable and then to append additional parameters on to the request URL.

Example requests: Posts - https://www.example.com/wp-json/wp/v2/posts? Posts from specific category - https://www.example.com/wp-json/wp/v2/posts?categories=44

My question is around how I should append additional parameters on to the end of the base url "https://www.example.com/wp-json/wp/v2/posts?"

Example scenarios:

• User clicks on input field to get posts from category id 44 - "https://www.example.com/wp-json/wp/v2/posts?categories=44" - User clicks on second input which is category 45, this is then appended to the url again as so: "https://www.example.com/wp-json/wp/v2/posts?categories=44,45"

What I need to understand is how I can remove the "categories" parameter if none of the inputs are "checked". There could be additional parameters at this url too, so there are examples where the user could begin to append quite a long series of parameters.

If none of the inputs are selected, as it stands the code in my example JS fiddle keeps the "categories" param in the url, but if none are selected in this category, it returns a bad request url. I need some help understanding some logic to remove additional parameters if no inputs are selected.

Here is my js fiddle, i've made comments throughout to help explain what I'm trying to achieve JSFiddle - https://jsfiddle.net/xun2bsyh/4/

Code also: