Regular expressions (regex) are powerful tools for pattern matching. Here are some advanced techniques:

  • Lookaheads/lookbehinds
    Use (?=...) or (?<=...) to assert conditions without consuming characters.

    Regular_Expression
    [Read more about lookahead assertions](/en/docs/regex_tutorial)

  • Capturing Groups
    Enclose patterns in (...) to extract matched substrings.

    Grouping
    Example: `(\d{3})-(\d{3})-(\d{4})` for phone numbers.

  • Greedy vs Lazy Matching
    Greedy quantifiers like * match as much as possible, while lazy ones *? match minimally.

    Greedy_Matching
    Tip: Add `?` after quantifiers to enable lazy behavior.

  • Atomic Groups
    Use (?>(...)) to prevent backtracking once a match is found.
    Explore regex performance optimizations

For visual learners, here are diagrams:

Regex_Flowchart
Regex_Diagram