Pass entire form as data in jQuery Ajax function

Use

serialize( )

var str = $("form").serialize();

Serialize a form to a query string, that could be sent to a server in an Ajax request.

serialize() is not a good idea if you want to send a form with post method. For example if you want to pass a file via ajax its not gonna work.

Suppose that we have a form with this id : "myform".

the better solution is to make a FormData and send it:

    let myform = document.getElementById("myform");
    let fd = new FormData(myform );
    $.ajax({
        url: "example.php",
        data: fd,
        cache: false,
        processData: false,
        contentType: false,
        type: 'POST',
        success: function (response) {
            // do something with the result
        }
    });

There's a function that does exactly this:

http://api.jquery.com/serialize/

var data = $('form').serialize();
$.post('url', data);

In general use serialize() on the form element.

Please be mindful that multiple <select> options are serialized under the same key, e.g.

<select id="foo" name="foo" multiple="multiple">
    <option value="1">one</option>
    <option value="2">two</option>
    <option value="3">three</option>
</select>

will result in a query string that includes multiple occurences of the same query parameter:

[path]?foo=1&foo=2&foo=3&someotherparams...

which may not be what you want in the backend.

I use this JS code to reduce multiple parameters to a comma-separated single key (shamelessly copied from a commenter's response in a thread over at John Resig's place):

function compress(data) {
    data = data.replace(/([^&=]+=)([^&]*)(.*?)&\1([^&]*)/g, "$1$2,$4$3");
    return /([^&=]+=).*?&\1/.test(data) ? compress(data) : data;
}

which turns the above into:

[path]?foo=1,2,3&someotherparams...

In your JS code you'd call it like this:

var inputs = compress($("#your-form").serialize());

Hope that helps.