Help creating a regex

Question

I need to know if a string matches several different criteria. I try to solve this using a regex and then see if it matches (in Java: str.matches (myRegex);), but I can't figure it out correctly.

The criteria are as follows:

• Corresponding line is constructed of 4 letters, [AZ]
• Perhaps it may precede (but not necessarily) one of the "-", "+" or "VC"
• It should match only strings containing exactly 4 letters (and possibly the preceding characters)

Examples:

• "SHSN" → match
• "+ SHRA" → match
• "VCSHRA" → match
• "CAVOK" → no match
• "- + SHSN" → no match

Can this be done in one regex? Or should it be done in code or in a combination of the two?

Thanks,

Linus

Answer 1

Try this regex:

^([+-]|VC)?[AZ]{4}$