如何使用单个 xpath 表达式获得 H1,H2,H3,... [英] How to get H1,H2,H3,... using a single xpath expression

问题描述

如何在单个 xpath 表达式中获取 H1、H2、H3 内容?

How can I get H1,H2,H3 contents in one single xpath expression?

我知道我可以做到这一点.

I know I could do this.

//html/body/h1/text()
//html/body/h2/text()
//html/body/h3/text() 

等等.

推荐答案

使用:

/html/body/*[self::h1 or self::h2 or self::h3]/text()

以下表述不正确:

//html/body/*[local-name() = "h1"  
           or local-name() = "h2"  
           or local-name() = "h3"]/text()  

因为它可能选择作为unwanted:h1、different:h2、someWeirdNamespace:h3 的子节点的文本节点.

because it may select text nodes that are children of unwanted:h1, different:h2, someWeirdNamespace:h3.

另一个建议:当 XML 文档的结构是静态已知的时，始终避免使用 //.使用 // 通常会导致显着的低效率，因为它会导致遍历在上下文节点中旋转的完整文档(子)树.

Another recommendation: Always avoid using // when the structure of the XML document is statically known. Using // most often results in significant inefficiencies because it causes the complete document (sub)tree roted in the context node to be traversed.

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