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$