38 lines
1.0 KiB
Markdown
38 lines
1.0 KiB
Markdown
---
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title: HTML DOM querySelector()
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localeTitle: HTML DOM querySelector()
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---
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Document方法`querySelector()`返回文档中与指定选择器或选择器组匹配的`first` Element。如果未找到匹配项,则返回null。
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**HTML内容:**
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```html
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<div id="id-example"></div>
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<div class="class-example"></div>
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<a>element-example</a>
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```
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**JavaScript内容:**
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```javascript
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document.querySelector("#id-example"); // Returns the element with id "id-example"
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document.querySelector(".class-example"); // Returns the element with class "class-example"
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document.querySelector("a"); // Returns the "a" element
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```
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注意`querySelector()`返回第一个匹配元素,返回所有匹配项,改为使用querySelectorAll()方法。
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```html
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<div id="example">First</div>
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<div id="example">Second</div>
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```
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```javascript
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document.querySelector("#example"); // Returns only the element containing 'First'
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```
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#### 更多信息:
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[MDN - document.querySelector()](https://developer.mozilla.org/en-US/docs/Web/API/Document/querySelector) |