JSFiddle - React, Tailwind, and code Playground

HTML

<form><input type="hidden" name="ddff" value ="ggg"/><input type="hidden" name="hhddff" value ="988"/><input type="hidden" name="hj" value ="g99gg"/>
    <input type='button' name='submitData' value='Submit' onClick='submitData();'>
</form>

JavaScript

var data = {}
$('form :input:hidden').each(function(){
    data[this.name] = this.value;
});
alert(JSON.stringify(data))