Adding a parameter to the URL with JavaScript

Question

In a web application that makes use of AJAX calls, I need to submit a request but add a parameter to the end of the URL, for example:

Original URL:

Answer 1

Vianney Bajart's answer is correct; however, URL will only work if you have the complete URL with port, host, path and query:

new URL('http://server/myapp.php?id=10&enabled=true')

And URLSearchParams will only work if you pass only the query string:

new URLSearchParams('?id=10&enabled=true')

If you have an incomplete or relative URL and don't care for the base URL, you can just split by ? to get the query string and join later like this:

function setUrlParams(url, key, value) {
  url = url.split('?');
  usp = new URLSearchParams(url[1]);
  usp.set(key, value);
  url[1] = usp.toString();
  return url.join('?');
}

let url = 'myapp.php?id=10';
url = setUrlParams(url, 'enabled', true);  // url = 'myapp.php?id=10&enabled=true'
url = setUrlParams(url, 'id', 11);         // url = 'myapp.php?id=11&enabled=true'

Not compatible with Internet Explorer.