Practice

Hands-on regular-expression lessons - write real patterns, run them instantly, and get checked by real tests.

Lessons

1. Literal matching and .test()
2. Character classes
3. Quantifiers
4. Anchors and boundaries
5. Groups and capture
6. Practical validation
7. Capstone: extracting prices
8. Capstone: normalizing usernames
9. Lookahead
10. Backreferences
11. Greedy vs. lazy quantifiers
12. Global flag: find and replace all
13. Capstone: reformatting names
14. Fix the bug: the pattern that accepts junk