JSFiddle - React, Tailwind, and code Playground

HTML

<form onsubmit="return checkForm(this);">
<input type="text" />
<input type="checkbox" />
<input type="radio" />
<select>
    <option value="">Empty</option>
    <option value="1">1</option>
    <option value="2">2</option>
</select>
<textarea></textarea>
<button type="submit">Send</button>
</form>

JavaScript

function checkForm(oForm) {
    for (var i = 0; i < oForm.elements.length; i++) {
        if (GetElementValue(oForm.elements[i]).length > 0)
            return true;
    }
    alert("all empty");
    return false;
}

function GetElementValue(element) {
    if ((element.type === "checkbox" || element.type === "radio") && element.checked === false)
        return "";
    return element.value;
}