• Chapter 1: Getting Started with Stylus Studio
• Chapter 2: Editing and Querying XML
• Chapter 3: Converting Non-XML Files to XML
• Chapter 4: Working with XSLT
• Chapter 5: Creating XSLT Using the XSLT Mapper
• Chapter 6: Debugging Stylesheets
• Chapter 7: Defining XML Schemas
• Chapter 8: Defining Document Type Definitions
• Chapter 9: Writing XPath Expressions
  • About the XPath Processor
  • Sample Data for Examples and Testing
  • Getting Started with Queries
  • Specifying the Nodes to Evaluate
  • Handling Strings and Text
  • Specifying Boolean Expressions and Functions
  • Specifying Number Operations and Functions
  • Comparing Values
  • Finding a Particular Node
  • Obtaining a Union
  • Obtaining Information About a Node or a Node Set
  • Using XPath Expressions in Stylesheets
  • Accessing Other Documents During Query Execution
  • XPath Quick Reference
• Chapter 10: Working with XQuery in Stylus Studio
• Chapter 11: Composing Web Service Calls
• Chapter 12: Accessing Relational Data as XML
• Chapter 13: Extending Stylus Studio
• Chapter 14: Stylus Studio Reference

Home > Online Product Documentation > Table of Contents > Comparing Single Values With <=, <, >, and >=

Comparing Single Values With <=, <, >, and >=

When neither object to be compared is a node set and the operator is <=, <, >=, or >, the XPath processor performs the comparison by converting both objects to numbers and comparing the numbers according to IEEE 754.

The XPath processor always evaluates these comparisons in terms of numbers. You cannot use the less than and greater than operators to order strings. This is especially important to remember when you compare a number with a string. For example, suppose you want to evaluate the expression

a < "foo"
               

            

The return value is always false. This is because number("foo") returns NaN, and the resulting comparison, shown below, is always false.

a < NaN