JSFiddle - React, Tailwind, and code Playground

HTML

<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="button" id="checkValue" value="Check value" />
    <input type="reset" value="Reset Form" />
</form>

JavaScript

;(function (undefined) {
    var i, k, form, element,
        formInfo = [];

    for (i = 0; i < document.forms.length; i++) {
        form = document.forms[i];
        
        formInfo[i] = {};
        
        for (j = 0; j < form.elements.length; j++) {
            element = form.elements[j];
            
            if (!element || element.type !== 'hidden')
                continue;
            
            formInfo[i][j] = element.value;
        }
        
        form.addEventListener('reset', onFormReset);
    }
    
    function onFormReset(e) {
        var i, k;
        for (i = 0; i < document.forms.length; i++) {
            if (document.forms[i] === this) {
                for (k in formInfo[i]) {
                    this.elements[k].value = formInfo[i][k];
                }
            }   
        }
    }
})();

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

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

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