Master the fundamental shorthand classes of regular expressions to capture letters, numbers, and spaces.

Learn to pin your searches. Restrict regex matches to boundaries, starts, and ends of words.

Master matching specialized sets, ranges, and negative gates.

Write ultra-lean patterns by squeezing repeated blocks and optional matching pathways.

Validate real-world string formats — hex colors, times, versions, slugs and more. The traps are the malformed cases real validators must reject.

Backreferences, lookahead, and clever tricks. Each trap defeats the lazy solution, so par actually means something here.

Validate the formats real apps deal with — ZIP, price, email, phone, dates, passwords, cards. The traps are the malformed inputs a real validator must reject.

The legendary tricks — automata, palindromes, prime lengths. Mostly impossible to find cold; pure regex wizardry.

Everyday line-and-text validation — comments, blank lines, extensions, CSV, mentions, trailing whitespace. The bread and butter of real regex.

Sharpen the essentials — word boundaries, signed numbers, spacing, repeats, and case. Short rules, sneaky traps.

Validate genetic sequences — bases, codons, start/stop signals. Real rules molecular biologists rely on.

Parse algebraic chess notation — squares, moves, captures, castling. The grammar of the game.

Validate chemical notation — element symbols, molecular formulas, ionic charges, pH. The grammar of the lab.

Parse musical notation — note names, octaves, time signatures, chords. The written language of sound.

The shapes of source code — identifiers, casing, calls, imports, key/value. Naming rules with teeth.

Web and systems formats — URLs, ports, git hashes, HTML tags, colors, MAC addresses.