具備HTML(部分):爲什麼element.classList.add('class-name');不管用?
<div class="modal-write-us">
<form class="modal-write-us-form" action="" method="post">
<label>
<input type="text" name="user-name" required>
</label>
<label>
<input type="text" name="e-mail" required>
</label>
<label for="text-field"></label>
<textarea name="text" rows="5" id="text-field" required></textarea>
</form>
<div class="modal-write-us-button">
<button class="btn btn-red" type="submit">Submit</button>
</div>
</div>
我需要添加類「模態錯誤」爲div.modal,寫我們,如果提交的表單有空場/場。
JS:
var modalWriteUs = document.querySelector('.modal-write-us');
var form = modalWriteUs.querySelector('form');
var userName = modalWriteUs.querySelector('[name=user-name]');
var eMail = modalWriteUs.querySelector('[name=e-mail]');
var textArea = modalWriteUs.querySelector('[name=text]');
form.addEventListener('submit', function(event) {
if (!userName.value || !eMail.value || !textArea.value) {
event.preventDefault();
modalWriteUs.classList.add('modal-error');
}
});
但是類不會被添加。我的錯誤在哪裏?
你確定你是通過這種條件嗎?添加一個console.log來驗證 –
@Lina你的CSS屬性選擇器需要引號。例如:'modalWriteUs.querySelector('[name =「user-name」]');' – Nayuki
@Nayuki屬性選擇器的值也可以是標識符。 – Oriol