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XPath Syntax
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XPath uses path expressions to select nodes or node-sets in an XML document. The node is selected by following a path or steps.
The XML Example Document
We will use the following XML document in the examples below.
<?xml version="1.0" encoding="UTF-8"?>
<bookstore>
<book>
<title lang="en">Harry Potter</title>
<price>29.99</price>
</book>
<book>
<title lang="en">Learning XML</title>
<price>39.95</price>
</book>
</bookstore>
Selecting Nodes
XPath uses path expressions to select nodes in an XML document. The node is selected by following a path or steps. The most useful path expressions are listed below:
Expression Description
nodename Selects all nodes with the name "nodename"
/ Selects from the root node
// Selects nodes in the document from the current node that match the selection no matter where they are
. Selects the current node
.. Selects the parent of the current node
@ Selects attributes
In the table below we have listed some path expressions and the result of the expressions:
Path Expression Result
bookstore Selects all nodes with the name "bookstore"
/bookstore Selects the root element bookstore
Note: If the path starts with a slash ( / ) it always represents an absolute path to an element!
bookstore/book Selects all book elements that are children of bookstore
//book Selects all book elements no matter where they are in the document
bookstore//book Selects all book elements that are descendant of the bookstore element, no matter where they are under the bookstore element
//@lang Selects all attributes that are named lang
Predicates
Predicates are used to find a specific node or a node that contains a specific value.
Predicates are always embedded in square brackets.
In the table below we have listed some path expressions with predicates and the result of the expressions:
Path Expression Result
/bookstore/book[1] Selects the first book element that is the child of the bookstore element.
Note: In IE 5,6,7,8,9 first node is[0], but according to W3C, it is [1]. To solve this problem in IE, set the SelectionLanguage to XPath:
In JavaScript: xml.setProperty(" SelectionLanguage","XPath");
/bookstore/book[last()] Selects the last book element that is the child of the bookstore element
/bookstore/book[last()-1] Selects the last but one book element that is the child of the bookstore element
/bookstore/book[position()<3] Selects the first two book elements that are children of the bookstore element
//title[@lang] Selects all the title elements that have an attribute named lang
//title[@lang='en'] Selects all the title elements that have a "lang" attribute with a value of "en"
/bookstore/book[price>35.00] Selects all the book elements of the bookstore element that have a price element with a value greater than 35.00
/bookstore/book[price>35.00]/ title Selects all the title elements of the book elements of the bookstore element that have a price element with a value greater than 35.00
Selecting Unknown Nodes
XPath wildcards can be used to select unknown XML nodes.
Wildcard Description
* Matches any element node
@* Matches any attribute node
node() Matches any node of any kind
In the table below we have listed some path expressions and the result of the expressions:
Path Expression Result
/bookstore/* Selects all the child element nodes of the bookstore element
//* Selects all elements in the document
//title[@*] Selects all title elements which have at least one attribute of any kind
Selecting Several Paths
By using the | operator in an XPath expression you can select several paths.
In the table below we have listed some path expressions and the result of the expressions:
Path Expression Result
//book/title | //book/price Selects all the title AND price elements of all book elements
//title | //price Selects all the title AND price elements in the document
/bookstore/book/title | //price Selects all the title elements of the book element of the bookstore element AND all the price elements in the document
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TUTORIAL HOME
XPath Syntax
❮ Previous Next ❯
XPath uses path expressions to select nodes or node-sets in an XML document. The node is selected by following a path or steps.
The XML Example Document
We will use the following XML document in the examples below.
<?xml version="1.0" encoding="UTF-8"?>
<bookstore>
<book>
<title lang="en">Harry Potter</title>
<price>29.99</price>
</book>
<book>
<title lang="en">Learning XML</title>
<price>39.95</price>
</book>
</bookstore>
Selecting Nodes
XPath uses path expressions to select nodes in an XML document. The node is selected by following a path or steps. The most useful path expressions are listed below:
Expression Description
nodename Selects all nodes with the name "nodename"
/ Selects from the root node
// Selects nodes in the document from the current node that match the selection no matter where they are
. Selects the current node
.. Selects the parent of the current node
@ Selects attributes
In the table below we have listed some path expressions and the result of the expressions:
Path Expression Result
bookstore Selects all nodes with the name "bookstore"
/bookstore Selects the root element bookstore
Note: If the path starts with a slash ( / ) it always represents an absolute path to an element!
bookstore/book Selects all book elements that are children of bookstore
//book Selects all book elements no matter where they are in the document
bookstore//book Selects all book elements that are descendant of the bookstore element, no matter where they are under the bookstore element
//@lang Selects all attributes that are named lang
Predicates
Predicates are used to find a specific node or a node that contains a specific value.
Predicates are always embedded in square brackets.
In the table below we have listed some path expressions with predicates and the result of the expressions:
Path Expression Result
/bookstore/book[1] Selects the first book element that is the child of the bookstore element.
Note: In IE 5,6,7,8,9 first node is[0], but according to W3C, it is [1]. To solve this problem in IE, set the SelectionLanguage to XPath:
In JavaScript: xml.setProperty("
/bookstore/book[last()] Selects the last book element that is the child of the bookstore element
/bookstore/book[last()-1] Selects the last but one book element that is the child of the bookstore element
/bookstore/book[position()<3] Selects the first two book elements that are children of the bookstore element
//title[@lang] Selects all the title elements that have an attribute named lang
//title[@lang='en'] Selects all the title elements that have a "lang" attribute with a value of "en"
/bookstore/book[price>35.00] Selects all the book elements of the bookstore element that have a price element with a value greater than 35.00
/bookstore/book[price>35.00]/
Selecting Unknown Nodes
XPath wildcards can be used to select unknown XML nodes.
Wildcard Description
* Matches any element node
@* Matches any attribute node
node() Matches any node of any kind
In the table below we have listed some path expressions and the result of the expressions:
Path Expression Result
/bookstore/* Selects all the child element nodes of the bookstore element
//* Selects all elements in the document
//title[@*] Selects all title elements which have at least one attribute of any kind
Selecting Several Paths
By using the | operator in an XPath expression you can select several paths.
In the table below we have listed some path expressions and the result of the expressions:
Path Expression Result
//book/title | //book/price Selects all the title AND price elements of all book elements
//title | //price Selects all the title AND price elements in the document
/bookstore/book/title | //price Selects all the title elements of the book element of the bookstore element AND all the price elements in the document
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