GUIDE深度 · Deep dive
Regex Basics: Classes, Quantifiers, Anchors
Start with character classes and quantifiers: \d digits, \w word characters, + one or more, * zero or more, ? zero or one. Anchors ^ and $ pin the string. Escape special characters.
Common symbols
\d digit, \w word character, \s whitespace.
+ / * / ? control repetition.
Anchors
^ start, $ end.
\b word boundary.
FAQ
What does . match?
Any character except newline by default.
How to match a literal dot?
Escape it as \.