javascript 元素javascript中的getElementsByTagName
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时间：2020-10-26 08:01:59 来源:igfitidea点击:
getElementsByTagName within an element javascript
提问by Sam Adamsh
Why does the following return 0?
为什么以下返回0？
<p id="g">
<div>kk</div>
<div>ee</div>
<div>jff</div>
</p>
<script type="text/javascript">
var ii = document.getElementById("g");
var hh = ii.getElementsByTagName('div');
document.write(hh.length);
</script>
回答by Tomalak
Because you can't have a <div>in a <p>. Paragraphs can only have inline elementsas children.
因为你不能有<div>a <p>。段落只能有内联元素作为子元素。
As soon as the parser encounters a <div>, it auto-closes the <p>.
一旦解析器遇到<div>，它就会自动关闭<p>。
Compare
比较
<p id="g">
<span>kk</span>
<div>ee</div>
<div>jff</div>
</p>
<script type="text/javascript">
var ii = document.getElementById("g");
var hh = ii.getElementsByTagName('span');
alert(hh.length);
</script>?
