javascript - 检查输入字段的值并添加一个类

Question

我有两个输入字段和一个提交按钮(内联显示)。填写输入字段后，我试图将一个类添加到下一个兄弟。因此，如果填写了名字输入字段，则向电子邮件输入字段添加一个类，如果填写了电子邮件输入字段，则向下一个输入字段添加一个类，依此类推...

到目前为止，这是我的代码:

$('.form-display #mce-FNAME').blur(function() {
     if($.trim(this.value).length) {
        $('#mce-EMAIL').toggleClass('animated pulse');
     }else if(...){ }...
});

我的 HTML 看起来像这样:

<div class="form-display">
    <div class="mc-field-group">
        <label for="mce-FNAME">First Name </label>
        <input type="text" value="" name="FNAME" class="" id="mce-FNAME">
    </div>
    <div class="mc-field-group">
        <label for="mce-EMAIL">Email Address </label>
        <input type="email" value="" name="EMAIL" class="required email" id="mce-EMAIL">
    </div>
    <input type="submit" value="Subscribe" name="subscribe" id="mc-embedded-subscribe" class="button">
</div>

Answer 1

将除提交按钮之外的所有输入抓取到一个集合中。

在输入时，根据当前输入是否有值切换下一个输入的类:

var inputs = $('.form-display input').not(':submit');

inputs.on('input', function() {
  $(inputs[inputs.index(this) + 1]).toggleClass('animated pulse', this.value > '');
});

Fiddle

片段:

var inputs = $('.form-display input').not(':submit');  //all inputs except submit button

inputs.on('input', function() {
  $(inputs[inputs.index(this) + 1]).toggleClass('animated pulse', this.value > '');
});

.animated.pulse {
  background: yellow;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="form-display">
  <div class="mc-field-group">
    <label for="mce-FNAME">First Name </label>
    <input type="text" value="" name="FNAME" class="" id="mce-FNAME">
  </div>
  <div class="mc-field-group">
    <label for="mce-EMAIL">Email Address </label>
    <input type="email" value="" name="EMAIL" class="required email" id="mce-EMAIL">
  </div>
  <div class="mc-field-group">
    <label for="mce-CITY">City </label>
    <input type="text" value="" name="EMAIL" class="required email" id="mce-EMAIL">
  </div>
  <div class="mc-field-group">
    <label for="mce-STATE">State </label>
    <input type="email" value="" name="EMAIL" class="required email" id="mce-EMAIL">
  </div>
  <div class="mc-field-group">
    <label for="mce-ZIP">Zip </label>
    <input type="email" value="" name="EMAIL" class="required email" id="mce-EMAIL">
  </div>
  <input type="submit" value="Subscribe" name="subscribe" id="mc-embedded-subscribe" class="button">
</div>