How to Match US ZIP Codes with Regex?

^(\d{5})(?:-(\d{4}))?$

This regex pattern matches US ZIP codes in both 5-digit and ZIP+4 formats.

1. The pattern starts with ^ to indicate the beginning of the string.
2. The \d{5} matches exactly five digits representing the standard ZIP code.
3. The (?:...) is a non-capturing group that allows for optional matching.
4. The - matches the hyphen in the ZIP+4 format.
5. The \d{4} matches exactly four digits representing the extended ZIP code.
6. $ indicates the end of the string.

• Input with letters or special characters will not match.
• ZIP codes with less than 5 digits will not match.
• ZIP codes with more than 10 characters will not match.
• Incorrect formats like 1234 or 12345-678 will not match.