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• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

DocumentFragment.querySelector() method returns the first element, or null if no matches are found, within the DocumentFragment (using depth-first pre-order traversal of the document's nodes) that matches the specified group of selectors.

If the selector matches an ID and this ID is erroneously used several times in the document, it returns the first matching element.

If the selectors specified in parameter are invalid a DOMException 采用 SYNTAX_ERR value is raised.

句法

element = documentfragment.querySelector(selectors);
					

参数

selectors

是 DOMString containing one or more CSS selectors separated by commas.

范例

基本范例

In this basic example, the first element in the DocumentFragment with the class " myclass " is returned:

var el = documentfragment.querySelector(".myclass");
					

CSS syntax and the method's argument

The string argument pass to querySelector must follow the CSS syntax. To match ID or selectors that do not follow the CSS syntax (by using semicolon or space inappropriately for example), it's mandatory to escape the wrong character with a double back slash:

<div id="foo\bar"></div>
<div id="foo:bar"></div>
<script>
document.querySelector('#foo\bar')    // Does not match anything
document.querySelector('#foo\\\\bar') // Match the first div
document.querySelector('#foo:bar')     // Does not match anything
document.querySelector('#foo\\:bar')   // Match the second div
</script>
					

规范

规范	状态	注释
Selectors API Level 2 The definition of 'DocumentFragment.querySelector' in that specification.	过时	无变化自 Selectors API Level 1
Selectors API Level 1 The definition of 'DocumentFragment.querySelector' in that specification.	过时	初始定义。

浏览器兼容性

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
querySelector	Chrome 1	Edge 12	Firefox 3.5	IE 9	Opera 10	Safari 3.2	WebView Android Yes	Chrome Android Yes	Firefox Android 4	Opera Android 10.1	Safari iOS 3.2	Samsung Internet Android Yes

图例

完整支持

完整支持

另请参阅

• DocumentFragment interface it belongs to.

元数据

• 最后修改： 2019 年 3 月 23 日

相关话题

1. DOM (文档对象模型)
2. DocumentFragment
3. 构造函数

   1. DocumentFragment()
4. 特性

   1. childElementCount
   2. children
   3. firstElementChild
   4. lastElementChild
5. 方法

   1. append()
   2. prepend()
   3. querySelector()
   4. querySelector()
   5. querySelectorAll()
   6. querySelectorAll()
   7. replaceChildren()
6. 继承：

   1. 节点
   2. EventTarget
7. DOM 相关页面

   1. AbortController
   2. AbortSignal
   3. AbstractRange
   4. Attr
   5. ByteString
   6. CDATASection
   7. CSSPrimitiveValue
   8. CSSValue
   9. CSSValueList
   10. CharacterData
   11. ChildNode
   12. 注释
   13. CustomEvent
   14. DOMConfiguration
   15. DOMError
   16. DOMErrorHandler
   17. DOMException
   18. DOMImplementation
   19. DOMImplementationList
   20. DOMImplementationRegistry
   21. DOMImplementationSource
   22. DOMLocator
   23. DOMObject
   24. DOMParser
   25. DOMPoint
   26. DOMPointInit
   27. DOMPointReadOnly
   28. DOMRect
   29. DOMString
   30. DOMTimeStamp
   31. DOMTokenList
   32. DOMUserData
   33. Document
   34. DocumentType
   35. 元素
   36. ElementTraversal
   37. Entity
   38. EntityReference
   39. 事件
   40. EventTarget
   41. HTMLCollection
   42. MutationObserver
   43. 节点
   44. NodeFilter
   45. NodeIterator
   46. NodeList
   47. NonDocumentTypeChildNode
   48. ProcessingInstruction
   49. PromiseResolver
   50. 范围
   51. StaticRange
   52. 文本
   53. TextDecoder
   54. TextEncoder
   55. TimeRanges
   56. TreeWalker
   57. TypeInfo
   58. USVString
   59. UserDataHandler
   60. XMLDocument