XPath Axes

Estimated study time: 12 minutes.

An axis in XPath defines the direction you move through the document tree relative to a starting node — not just downward to children, but upward to ancestors, sideways to siblings, and more.

Common Axes

child::module            <!-- direct children named module -->
parent::course            <!-- the parent node -->
ancestor::course           <!-- all ancestor nodes named course -->
descendant::module         <!-- all descendants, any depth, named module -->
following-sibling::module  <!-- sibling nodes that come after this one -->
preceding-sibling::module  <!-- sibling nodes that come before this one -->
self::course                <!-- the current node itself -->

Shorthand You Already Know

Many everyday XPath expressions are actually shorthand for the child and descendant axes:

• module is shorthand for child::module
• //module is shorthand for descendant-or-self::node()/child::module
• @id is shorthand for attribute::id

Practical Example

//module[text()='SQL for Analysis']/following-sibling::module

This finds the module named "SQL for Analysis," then selects whichever module elements come after it as siblings.