XPath

XPath query language for XML — the LINQ of the XML world

#XPath

XPath is a query language for selecting nodes in XML documents. The XML world has used XPath to query document trees since 1999.

For .NET developers: XPath resembles LINQ for XML. Both let a developer query a tree of data with a compact, declarative syntax.

XPath is not a standalone tool. XSLT uses XPath for matching and selecting nodes. XQuery uses XPath as its navigation syntax. XPath is also available directly in .NET through XPathNavigator and through PhoenixmlDb.

#What's Here

• Path Expressions — The core of XPath: navigating the document tree with /, //, predicates, and axes. This is where most of your day-to-day work happens.

• Functions — Comprehensive reference for XPath 4.0's 240+ built-in functions, organized by category: string, numeric, date/time, sequence, map, array, math, higher-order, and more.

• Operators and Comparisons — Arithmetic, comparison, logical operators, and the difference between value and general comparisons.

• Data Types — How XPath's type system works, type casting, and interaction with schema types.

#XPath by Example

Given this XML:

<catalog>
  <book isbn="978-0-123456-78-9" category="programming">
    <title>Effective C#</title>
    <author>Bill Wagner</author>
    <price currency="USD">39.99</price>
    <published>2017-03-15</published>
  </book>
  <book isbn="978-0-987654-32-1" category="data">
    <title>XML in a Nutshell</title>
    <author>Elliotte Harold</author>
    <price currency="USD">49.99</price>
    <published>2004-09-01</published>
  </book>
</catalog>
                                  

XPath expressions are more concise than the equivalent LINQ code. XPath also works with any XML tool, not only .NET.