XPath Operators and Functions: Mastering XML Data Manipulation
Learn how to use XPath operators and functions to perform calculations, comparisons, and data manipulation on XML documents. This comprehensive guide categorizes various XPath operators and functions, providing examples and explanations to enhance your XML data processing skills.
XPath Operators and Functions
Introduction
XPath uses operators and functions to perform calculations and comparisons on nodes within an XML document. An XPath expression produces a result that can be a node-set, a string, a boolean value, or a number. This guide categorizes and explains the various operators used in XPath expressions.
XPath Operators: A Summary
Here's a summary of the operators available in XPath:
| Operator | Description |
|---|---|
| |
Union: Combines two node-sets. |
+ |
Addition |
- |
Subtraction |
* |
Multiplication |
div |
Division |
= |
Equals |
!= |
Not equals |
< |
Less than |
<= |
Less than or equals |
> |
Greater than |
>= |
Greater than or equals |
or |
Logical OR |
and |
Logical AND |
mod |
Modulus (remainder after division) |
Categorization of XPath Operators and Functions
XPath operators and functions can be grouped into these categories:
- Comparison Operators: Used to compare values (e.g.,
=,!=,<,>). - Boolean Operators: Perform logical operations (
and,or,not). - Number Functions/Operators: Mathematical functions and operators for numeric values.
- String Functions: Functions for manipulating strings (e.g., `substring`, `contains`, `concat`).
- Node Functions/Operators: Functions and operators that work on nodes in the XML document (e.g., `count`, `position`, `last`).
Conclusion
XPath's operators and functions enable you to perform various calculations, comparisons, and manipulations on the nodes within an XML document, making it a versatile tool for data extraction and processing.