js中获取某个类下的某个标签，提示错误？

Question

html结构为：

<nav class="nav-class">

    <ul class="ul-class">

        <li class="li-class"><a class="a-class">链接1</a></li>

        <li class="li-class"><a class="a-class">链接2</a></li>

        <li class="li-class"><a class="a-class">链接3</a></li>

        <li class="li-class"><a class="a-class">链接4</a></li>

        <li class="li-class">

            <a class="a-class">链接5</a>

            <ul>

                <li class="li-class"><a class="a-class">链接6</a></li>

                <li class="li-class"><a class="a-class">链接7</a></li>

            </ul>

        </li>

    </ul>

</nav>

JS获取 nav-class 下的 a 标签：

var urlLink = document.getElementsByClassName('nav-class').getElementsByTagName('a'), find = false;

提示错误，这样的应该如何获取？谢谢

Answer 1

先给代码：var urlLink = document.getElementsByClassName('nav-class').item(0).getElementsByTagName('a').item(0);不管是Document还是Element对象，你调getElements~返回的就是个集合，所以你要想不这么麻烦，要不用id要不就上个querySelectorAll得了……