XPath Guide
XPath expression examples extract information from an XML document by evaluating those expressions. XPath stands for XML Path Language; also XPath uses "path like" syntax to identify and navigate nodes in an XML document.
XPath Expression
XPath uses expressions to select nodes or node-sets in an XML document.
These path expressions look very much like the path expressions you use with traditional computer file systems:
XPath Syntax
XPath uses path expressions to select nodes or node-sets in an XML document. The node is selected by following a path or steps.
<?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. |
The table below lists some path expressions and the result of the expressions:
| Expression | Results |
|---|---|
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.
The table below lists some path expressions with predicates and the result of the expressions:
| 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]. |
/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 |
The table below lists some path expressions and the result of the expressions:
| 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.
The table below lists some path expressions and the result of the expressions:
| Expression | Result |
|---|---|
//book/title | //book/price |
//title | //price |
/bookstore/book/title | //price |
XPath Operators
Below is a list of the operators that can be used in XPath expressions:
| Operator | Description | Example |
|---|---|---|
| ` | ` | Computes two node-sets |
+ | Addition | 6 + 4 |
- | Subtraction | 6 - 4 |
\* | Multiplication | 6 * 4 |
div | Division | 8 div 4 |
= | Equal | price=9.80 |
!= | Not equal | price!=9.80 |
\< | Less than | price<9.80 |
\<= | Less than or equal to | price<=9.80 |
\> | Greater than | price>9.80 |
\>= | Greater than or equal to | price>=9.80 |
or | or | price=9.80 or price=9.70 |
and | and | price>9.00 and price<9.90 |
mod | Modulus (division remainder) | 5 mod 2 |
Example
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<employees>
<employee id="1">
<firstName>Lokesh</firstName>
<lastName>Gupta</lastName>
<department>
<id>101</id>
<name>IT</name>
</department>
</employee>
<employee id="2">
<firstName>Brian</firstName>
<lastName>Schultz</lastName>
<department>
<id>102</id>
<name>HR</name>
</department>
</employee>
<employee id="3">
<firstName>Alex</firstName>
<lastName>Kolenchisky</lastName>
<department>
<id>103</id>
<name>FINANCE</name>
</department>
</employee>
<employee id="4">
<firstName>Amit</firstName>
<lastName>Jain</lastName>
<department>
<id>104</id>
<name>HR</name>
</department>
</employee>
<employee id="5">
<firstName>David</firstName>
<lastName>Beckham</lastName>
<department>
<id>105</id>
<name>DEVOPS</name>
</department>
</employee>
</employees>
Now, refer to a few examples of how to build an XPath to get information based on various conditions on fields and attributes.
| Expression | Meaning |
|---|---|
/employees/employee/firstName/text() | Get all employee names |
/employees/employee/department/name/text() | Get all department names |
/employees/employee\[department/name='IT'\]/firstName/text() | Get all employees in IT |
/employees/employee\[@id=4\]/firstName/text() | Get employee by id |
/employees/employee\[@id>6\]/firstName/text() | Get employees whose Id is greater than 6 |
/employees/employee\[firstName = 'David'\]/department/name/text() | Get department for David |
/employees/employee/@id | Get all employee ids |
/employees/employee\[department/name='HR'\]/@id | Get all employee ids in HR department |
/employees/employee\[firstName='Alex'\]/@id | Get employee id of 'Alex' |
/employees/employee/@id\[. > 5\] | Get employee ids greater than 5 |
/employees/employee\[contains(@id,'1')\]/firstName/text() | Get employee whose id contains '1' |
descendant-or-self::\*\[contains(@id,'1')\]/firstName/text() | Get employee whose id contains 1 |
How to Check XPath Syntax
You can use https://codebeautify.org/Xpath-Tester and check the sample XML example and XPath expression to validate it is working as expected.
