Courses

XML and XPath courses

Two free courses that run entirely in the browser. XML Foundations teaches the language — elements, attributes, well-formedness, namespaces. The XPath course teaches how to query it. Both are hands-on: you type real expressions against real documents and get checked immediately.

XML Foundations

Start here if XML itself is new, or if terms like "well-formed", "default namespace", or "CDATA section" are fuzzy. 14 short lessons, each with an editable document you break and repair yourself.

  • Elements
  • Tree Relationships
  • Attributes
  • Well-formed XML
  • Empty Elements
  • Comments
  • Character Escapes
  • CDATA Sections
  • XML Declaration
  • Processing Instructions
  • Namespaces I: prefixes
  • Namespaces II: default namespaces
  • The DOM: a name for the tree
  • Bridge to XPath

Start XML Foundations

XPath

19 phases, roughly 107 lessons, from your first descendant path (//) to XPath 3.1 sequences and higher-order functions. Reading lessons introduce each phase, exercises check your expressions against the live engine, and a quiz closes each phase.

  • XML as a Tree
  • Navigation
  • Filtering
  • Logic & Combining
  • Node Types
  • Axes
  • Expressions
  • Functions: Strings & Numbers
  • Functions: Logic, Position & Sequences
  • Conditionals & Quantifiers
  • for, Iteration, and Sorting
  • Namespaces
  • Real-World Practice
  • Querying with Intent
  • Maps, Arrays & Higher-Order Functions
  • Performance, Pitfalls & Debugging
  • Tracks
  • 1.0 vs 3.1 Capstone
  • Where XPath Goes Next

Start the XPath course

After the courses

Challenges push you to find every valid solution rather than one. The Daily puzzle keeps the habit going. The Sandbox is where you do real work.

Challenges · Daily puzzle · Sandbox