Prompt for Writing a Regular Expression (Regex) (Free Copy-Paste Prompt)

Copy-ready prompt

Write a regular expression that [matches/validates/extracts]: [describe in plain English].
Flavor: [JavaScript / Python / PCRE / etc].
Requirements:
- Provide the regex and explain each part.
- Give 3 matching and 3 non-matching examples.
- Note edge cases it does or doesn't handle.
- Keep it as readable as possible.

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Why this prompt works

Regex is easy to get subtly wrong. This prompt returns the pattern with a part-by-part explanation and test cases, so you can verify it does exactly what you need instead of trusting an opaque string.

How to customize it

Specify the regex flavor; syntax differs across languages.
Test the provided examples before deploying it.
Ask for a simpler version if readability matters more than brevity.

Tip: replace the parts in [square brackets] with your own details before you send. The more specific you are — audience, tone, goal, constraints — the better the AI output.