Regular Expressions
The planned outline of 11 modules. Lessons are written, run and reviewed before they are published.
Planned outline
- Module 1
Foundations: what a regex is and how matching works
Coming soon - Module 2
Characters, escapes and character classes
Coming soon - Module 3
Anchors and boundaries
Coming soon - Module 4
Quantifiers: greedy, lazy and possessive
Coming soon - Module 5
Groups, alternation and backreferences
Coming soon - Module 6
Lookaround and advanced constructs
Coming soon - Module 7
Flags, modes and Unicode
Coming soon - Module 8
Flavours compared and regex in each language
Coming soon - Module 9
Regex in tools, spreadsheets, web standards and data cleaning
Coming soon - Module 10
Validation patterns and their limits
Coming soon - Module 11
Performance, ReDoS and security
Coming soon
Related tools
Regex Tester Live matches, capture groups and replace preview — safe from runaway patterns. Find and Replace Text Many find-and-replace rules at once, with regex, case options and highlighted changes. Email Extractor Paste text or HTML and get every address — deduplicated, grouped and ready to export. URL Extractor Every link in a page’s source or any text — cleaned up, counted and filterable.
Official documentation
- tc39.es/ecma262 (tc39.es)
- docs.python.org/3/library/re.html (docs.python.org)
- www.pcre.org/current/doc/html (pcre.org)
- github.com/google/re2/wiki/Syntax (github.com)
More in Programming languages
- Python (coming soon)
- SQL (PostgreSQL, MySQL, SQLite) (coming soon)
- JavaScript (ES2026) (coming soon)
- Java (JDK 25 LTS) (coming soon)
- All Languages tracks
- How we make lessons