regular expressions
did you know you can do matching inline too matching equivalent statements: test (\w+) \1; non-capture group (?:test)
lookaheads
- (?=pattern) true if pattern matches, but doesn’t touch the character pointer
- (?!pattern) true if pattern doesn’t match; also doesn’t advance pointer
- (?:pattern) will advance character pointer but will not create a capture group
- ^beginning of line
- end of line$