JSFiddle - React, Tailwind, and code Playground

HTML

<div id="mainDiv">
   <input type="text" name="text-1" /> <br/>

   <input type="radio" name="radio-1" />Yes
   <input type="radio" name="radio-1" />No <br/>

   <input type="text" name="text-2" /> <br/>
   <input type="text" name="text-3" /> <br/>
</div>
<input type="button" value="Get values!" id="button" />

JavaScript

function buildRequestStringData(form) {
    var select = form.find('select'),
        input = form.find('input'),
        requestString = '{';
    for (var i = 0; i < select.length; i++) {
        requestString += '"' + $(select[i]).attr('name') + '": "' +$(select[i]).val() + '",';
    }
    if (select.length > 0) {
        requestString = requestString.substring(0, requestString.length - 1);
    }
    for (var i = 0; i < input.length; i++) {
        if ($(input[i]).attr('type') !== 'checkbox') {
            requestString += '"' + $(input[i]).attr('name') + '":"' + $(input[i]).val() + '",';
        } else {
            if ($(input[i]).attr('checked')) {
                requestString += '"' + $(input[i]).attr('name') +'":"' + $(input[i]).val() +'",';
            }
        }
    }
    if (input.length > 0) {
        requestString = requestString.substring(0, requestString.length - 1);
    }
    requestString += '}';
    return requestString;
}

$('#button').click(function () {
    alert(buildRequestStringData($('#mainDiv')));
});