Common Real-World Patterns

Real-world regex patterns combine anchors, character classes, quantifiers, and groups. The key is to be specific about what varies and what is fixed.

Some common patterns:

**Email (simplified):** [\w.+\-]+@[\w\-]+\.[\w.\-]+ This is a simplified pattern that covers common email formats. It does not fully conform to RFC 5322 — for example, it does not handle quoted local parts or IP address domains. For most form validation, a simplified pattern plus a confirmation email is the recommended approach.

**US Phone:** \(?\d{3}\)?[\s\-.]?\d{3}[\s\-.]?\d{4}

**Hex color:** #[0-9a-fA-F]{6}(?:[0-9a-fA-F]{2})?

Building patterns step by step — fixed text first, then variable parts — makes complex patterns approachable. Remember that no single regex can validate every edge case — use them for common-case filtering and handle exceptions in code.