JSFiddle - React, Tailwind, and code Playground

HTML

<form id="form1" name="formone" class="myclass">
    <input type="text" id="txt11"  name="txt11" value="parvesh1"/>
    <input type="text" id="txt12"  name="txt12" value="parvesh5"/>
</form>

<form id="form1" name="formtwo" class="myclass">
    <input type="text" id="txt21" name="txt21" value="parvesh3"/>
    <input type="text" id="txt22" name="txt22" value="parvesh4"/>
</form>
<input type="button" id="button" value="Click Me"/>

JavaScript

(function ($) {
    $(document).ready(function(){
        alert("serialize data :" + $('.myclass').length);
         var mydata = null;
		$('#button').on('click', function (e) {
            var formdata = []
            $('.myclass').each(function(){
                formdata.push($(this).serialize());
            });
            var data = formdata.join('&');
            alert(data)
    });
	});
}(jQuery));