How can I get form data with JavaScript/jQuery?

Question

Is there a simple, one-line way to get the data of a form as it would be if it was to be submitted in the classic HTML-only way?

For example:

Answer 1

It is 2019 and there's a better way to do this:

const form = document.querySelector('form');
const data = new URLSearchParams(new FormData(form).entries());

or if you want a plain Object instead

const form = document.querySelector('form');
const data = Object.fromEntries(new FormData(form).entries());

although note that this won't work with duplicate keys like you get from multi-select and duplicate checkboxes with the same name.