How to convert Object to Json format including dynamic table using Javascript/jQuery

Question

How to convert javascript Object to Json format?

I can create object data when user submit the form and i dont know how to convert submit data like json format?

can you tell me how to do?

here is my sample code..,

FIDDLE HERE

Example

  "cashpayments": [
{
  "name": something,
  "email": something,
  "password": null
}]                        <<<<< --- LIKE THAT --- >>>>>

(function ($) {
    $.fn.serializeFormJSON = function () {

        var o = {};
        var a = this.serializeArray();
        $.each(a, function () {
            if (o[this.name]) {
                if (!o[this.name].push) {
                    o[this.name] = [o[this.name]];
                }
                o[this.name].push(this.value || '');
            } else {
                o[this.name] = this.value || '';
            }
        });
        return o;
    };
})(jQuery);

$('form').submit(function (e) {
    e.preventDefault();
    var data = $(this).serializeFormJSON();
    console.log(data);
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<form action="#" method="post">
    <div>
        <label for="name">Name</label>
        <input type="text" name="name" id="name" />
    </div>
    <div>
        <label for="email">Email</label>
        <input type="text" name="email" id="email" />
    </div>
    <div>
        <label for="password">Password</label>
        <input type="password" name="password" id="password" />
    </div>
    <p>
        <input type="submit" value="Send" />
    </p>
</form>