Here is a snippet of my code:

$ .ajax ({
    url: 'ajax / ajax.feedback.php',
    type: 'POST',
    data: 'author =' + author + '& amp; mail =' + mail + '& amp; subject =' + subject + '& amp; text =' + text +
      '& amp; checkbox [1] =' + checkbox [1] + '& amp; checkbox [2] =' + checkbox [2] + '& amp; checkbox [3] =' + checkbox [3] + '& amp; checkbox [ 4] = '+ checkbox [4] +' & amp; checkbox [5] = '+ checkbox [5] +
      '& amp; checkbox [6] =' + checkbox [6] + '& amp; checkbox [7] =' + checkbox [7] + '& amp; checkbox [8] =' + checkbox [8] + '& amp; checkbox [ 9] = '+ checkbox [9],
    success: ...

How easy is it to do? Just send an array? (and how to read it later in php? if there are any peculiarities) In Google – it’s not clear – you need to create an object, use json. In practice, nothing comes of it.

Answer 1, authority 100%

http://api.jquery.com/jQuery.post/

there is an example

$. post ("test.php", {'choices []': ["Jon", "Susan"] });

for your case there should be something like this:

$. post ('ajax / ajax.feedback.php',
  {'author': author, 'mail': mail, 'subject': subject, 'text': text, 'checkbox []': checkbox},
  function (html) {success ...
  });

and even easier, you can do this:

$. post ("test.php", $ ("# testform"). serialize ());

on the server, the whole thing will be in the $ _POST array;
it is enough to display it on the screen print_r ($ _ POST) and everything will become clear

Answer 2, authority 33%

Here’s an example using JSON:

var author = document.getElementById ("author"). value;
...
$ .ajax ({
  url: 'ajax / ajax.feedback.php',
  type: 'POST',
  data: ({author: author, id: id, mail: mail}),
  success: function (data) {}
});

data is received via the $ _POST array

Answer 3, authority 33%

As always, there are options:
1. Glue everything into a line with a separator (change all occurrences of the separator in the line to html equivalents) and send everything in one parameter. And on the server do explode (); .
2. Read here – http: //www.simplecoding .org / otpravka-dannyx-v-formate-json-s-pomoshhyu-javascript-i-jquery.html . It seems like everything is written.
Basically, the methods are similar.