How to prepare encoded POST data on javascript?

Question

I need to send data by POST method.

For example, I have the string \"bla&bla&bla\". I tried using encodeURI and got \"bla&bla&bla\" as t

Answer 1

More recent DOM APIs for URLSearchParams (and via URL, possibly others too) handle encoding in some cases. For example, create or use an existing URL object (like from an anchor tag) I map entries of an object as key value pairs for URL encoded params (to use for GET/POST/etc in application/x-www-form-urlencoded mimetype). Note how the emoji, ampersand and double quotes are encoded without any special handling (copied from the Chrome devtools console):

var url = new URL(location.pathname, location.origin);
    Object.entries({a:1,b:"