Regex
Documentation Cheatsheet: Dave Child, Dzone, RegexOne Tools: (Online) RegExr, Regex101, RagexPal, RegexPlanet, (Offline) Rad Software (free) or RegexBuddy (paid)
Strings processing and the Mighty RegExp are the main subject in this category.
Documentation Cheatsheet: Dave Child, Dzone, RegexOne Tools: (Online) RegExr, Regex101, RagexPal, RegexPlanet, (Offline) Rad Software (free) or RegexBuddy (paid)