我正在尝试从 <article class="birds"> 获取所有 child ，但无法到达 <li class="bird">Hawk 中的这些内容...我正在尝试用递归来做到这一点。
function traverse (node){
node = document.getElementsByClassName(node)[0];
for(let i=0; i<node.childNodes.length; i++){
let child = node.childNodes[i];
if(child.nodeName == '#text'){
continue;
}else{
console.log(child.nodeName.toLowerCase() +
": class=\"" + child.className +"\"");
if(child.nodeType === document.ELEMENT_NODE){
traverse(child.className);
}
}
}
}
traverse('birds');
<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<body>
<header>
<h1>Living Creatures</h1>
</header>
<section>
<article class="birds">
<h2 class="birds-heading">Birds</h2>
<ul class="birds-list">
<li class="bird">Nightingale</li>
<li class="bird">Owl</li>
<li class="bird">Hawk
<ul>
<li class="sub-bird">Black Hawk</li>
<li class="sub-bird">Chicago Hawk</li>
</ul>
</li>
<li id="eagle" class="bird">Eagle</li>
<li class="bird">Sparrow</li>
<li class="bird">Falcon</li>
<li class="bird">Blackbird</li>
</ul>
</article>
<article class="mammals">
<h2 class="mammal-heading">Mammals</h2>
<ol class="mammal-list">
<li id="dolphin" class="mammal">Dolphin</li>
<li class="mammal">Elephant</li>
<li class="mammal">Hyena</li>
</ol>
</article>
</section>
<script type="text/javascript" src="testing.js"></script>>
</body>
</html>
是因为<ul>元素没有类属性？我得到的输出是:
h2: class="birds-heading"
ul: class="birds-list"
li: class="bird"
最佳答案
根据我的理解，您正在尝试从容器 .birds 中获取所有 li。如果是，您可以直接使用 querySelectorAll 而不是手动遍历 DOM 并手动搜索。
function traverse(className, fetchElement){
return document.querySelectorAll("."+className +" " + fetchElement)
}
console.log(traverse('birds', 'li'))<section>
<article class="birds">
<h2 class="birds-heading">Birds</h2>
<ul class="birds-list">
<li class="bird">Nightingale</li>
<li class="bird">Owl</li>
<li class="bird">Hawk
<ul>
<li class="sub-bird">Black Hawk</li>
<li class="sub-bird">Chicago Hawk</li>
</ul>
</li>
<li id="eagle" class="bird">Eagle</li>
<li class="bird">Sparrow</li>
<li class="bird">Falcon</li>
<li class="bird">Blackbird</li>
</ul>
</article>
<article class="mammals">
<h2 class="mammal-heading">Mammals</h2>
<ol class="mammal-list">
<li id="dolphin" class="mammal">Dolphin</li>
<li class="mammal">Elephant</li>
<li class="mammal">Hyena</li>
</ol>
</article>
</section>关于JavaScript DOM 遍历，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/40651949/