从jQuery中的元素选择中按类获取元素

Example HTML:

示例HTML:

<ul class="nav">
    <li class="item">Item 1</li>
    <li class="item">Item 2</li>
    <li class="item active">Item 3</li>
    <li class="item">Item 4</li>
    <li class="item">Item 5</li>
</ul>
<ul class="nav">