如果文本字段为空，则在提交时发出 Javascript 警报

Question

所以我想在用户提交带有空文本字段的表单时提醒他们

HTML:

<form id="orderform">
    <input type="text" name="initials" id="initials" maxlength="3">
    <p class="center">
        <input type="image" src="#" id="submitbutton" name="submit" value="Place Order">
    </p>
</form>

Javascript:

$('#orderform').submit(function() {
    if($('#initials').length == 0){
        alert('Please fill out your initials.');
    }
});

Answer 1

只要确保你在某处返回 false-

$('#orderform').submit(function() {
    if($('#initials').val() == ''){
        alert('Please fill out your initials.');
        return false;
    }
});