JSFiddle - React, Tailwind, and code Playground

HTML

<form id="form">
    <input type="hidden" id="hidden" value="1" />
    <input type="checkbox" value="1" />
    <input type="button" id="setValue" value="Set value to 2" />
    <input type="reset" value="Reset Form" />
    <input type="button" id="checkValue" value="Check value" />
</form>

JavaScript

var form = $("#form"),
    hidden = $("#hidden"),
    setValueButton = $("#setValue"),
    checkValueButton = $("#checkValue");


setValueButton.click(function() {
    hidden.val(2);
});

checkValueButton.click(function() {
    alert(hidden.val());
});