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

You can also use the FormData Objects; The FormData object lets you compile a set of key/value pairs to send using XMLHttpRequest. Its primarily intended for use in sending form data, but can be used independently from forms in order to transmit keyed data.

        var formElement = document.getElementById("myform_id");
        var formData = new FormData(formElement);
        console.log(formData);