XPathExpression

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方法
范例
规范
浏览器兼容性
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This interface is a compiled XPath expression that can be evaluated on a document or specific node to return information from its DOM 树。 This is useful when an expression will be reused in an application, because it is just compiled once and all namespace prefixes which occur within the expression are preresolved.

Objects of this type are created by calling XPathEvaluator.createExpression() .

方法

XPathExpression.evaluate()

范例

The following example shows the use of the XPathExpression 接口。

HTML

<div>XPath example</div>
<div>Number of <div>s: <output></output></div>

JavaScript

var xpath = "//div";
var evaluator = new XPathEvaluator();
var expression = evaluator.createExpression(xpath);
var result = expression.evaluate(document, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE);
document.querySelector("output").textContent = result.snapshotLength;

结果

规范

规范	状态	注释
DOM (文档对象模型) 3 级 XPath 规范 The definition of 'XPathExpression' in that specification.	推荐	初始定义

浏览器兼容性

The compatibility table on 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
`XPathExpression`	Chrome Yes	Edge ≤18	Firefox Yes	IE ?	Opera Yes	Safari ?	WebView Android Yes	Chrome Android Yes	Firefox Android Yes	Opera Android Yes	Safari iOS ?	Samsung Internet Android Yes
`evaluate`	Chrome Yes	Edge 12	Firefox Yes	IE ?	Opera Yes	Safari ?	WebView Android Yes	Chrome Android Yes	Firefox Android Yes	Opera Android Yes	Safari iOS ?	Samsung Internet Android Yes

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方法

范例

HTML

JavaScript

结果

规范

浏览器兼容性

图例

另请参阅

元数据

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