Bootstrap Form Validation JS

Form Validation

<form class="needs-validation" novalidate>
    <div class="mb-3">
        <input type="email" class="form-control" required>
        <div class="valid-feedback">Looks good!</div>
        <div class="invalid-feedback">Please enter a valid email.</div>
    </div>
    <button type="submit" class="btn btn-primary">Submit</button>
</form>

<script>
document.querySelectorAll(".needs-validation").forEach(form => {
    form.addEventListener("submit", e => {
        if (!form.checkValidity()) { e.preventDefault(); e.stopPropagation(); }
        form.classList.add("was-validated");
    });
});
</script>