XPath syntax using XPath examples in C #

XPath can quickly navigate to a node or attribute in the XML. The XPath syntax is simple, but powerful enough, and it is also the basic knowledge of using XSLT.

Sample xml:

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<?xmlversion="1.0" encoding="utf-8" ?><pets>  <cat color="black" weight="10">    <price>100</price>    <desc>this is a black cat</desc>  </cat>  <catcolor="white" weight="9">    <price>80</price>    <desc>this is a white cat</desc>  </cat>  <catcolor="yellow" weight="15">    <price>80</price>    <desc>this is a yellow cat</desc>  </cat>  <dogcolor="black" weight="10">    <price>100</price>    <desc>this is a black dog</desc>  </dog>  <dogcolor="white" weight="9">    <price>80</price>    <desc>this is a white dog</desc>  </dog>  <dogcolor="yellow" weight="15">    <price>80</price>    <desc>this is a yellow dog</desc>  </dog></pets>

Syntax for XPath:

1. Symbols in XPath

Symbol	Description	Example	Example description
/	Represents the start of the root node selection	/pets	Select the root node pets
	Represents a spacer between a node and a child node	/pets/dog	Select the Dog node under the Pets node
Xx	Represents a lookup from an entire XML document regardless of the current node location	Price	Select all the price nodes in the document
.	A single English half-width period indicates the selection of the current node	/pets/.	Select Pets Node
..	Two points, which means selecting the parent node	/pets/dog[0]/.	Represents the Pets node, the parent node of the first dog node
@xx	Represents a selection attribute	dog/@color	Represents a collection of color properties that select all the dog nodes
[...]	The brackets indicate the selection criteria, which are the conditions in parentheses	dog[@color = ' White ']	All dog nodes that are color white
		DOG[/PRICE<100]	All dog nodes with a price byte point value less than 100
	The number in brackets is the node index, like in C # and other languages, array subscript is starting from 1	DOG[1]	A 1th dog node
		Dog[last ()]	The last dog node, finally () is an XPath built-in function
|	Single vertical bar indicates merge node combination	dog[@color = ' White ' | cat[@color = ' White ']	The Color property is White's dog node and the color property is White's cat node
*	An asterisk indicates the node or attribute of any name	dog/*	Represents all child nodes of the dog node
		dog/@*	All attribute nodes that represent the dog node

XPath syntax using XPath examples in C #