How to Write Regular Expressions with AI Quiz

Answers and explanations appear as you take the quiz.

1. Why is \d{5} without anchors a poor pattern for validating a ZIP code?
   • It only matches letters, not digits
   • It can match five digits inside a longer string like "1234567"
   • It is invalid syntax in most engines
   • It requires a special Unicode flag to work
2. What should a good regex request to an AI include?
   • A request for the shortest possible pattern
   • The name of your company and project
   • A promise that you will test it later
   • Examples that should and should not match, plus the regex flavor you use
3. Google Sheets uses the RE2 engine. What does RE2 deliberately leave out?
   • Backreferences and lookaround
   • Character classes like [A-Z]
   • Anchors like ^ and $
   • Quantifiers like + and *
4. What is catastrophic backtracking?
   • A regex running out of memory on very short strings
   • A regex tester highlighting the wrong characters
   • Exponential slowdown on patterns like (a+)+ when input almost matches
   • A regex that always returns an empty match
5. Applied to the text "<a><b>", what does the greedy pattern <.*> match?
   • Only "<a>"
   • Nothing at all
   • Only "<b>"
   • The whole string "<a><b>"
6. What does the guide suggest for validating email addresses?
   • Use one perfect regex that implements the full email standard
   • Use a simple sanity check plus a confirmation email
   • Never validate email addresses at all
   • Rely on lookbehind to check the domain
7. For parsing HTML, JSON or other nested structures, what does the guide recommend?
   • A longer and more detailed regex
   • Using lazy quantifiers everywhere
   • A real parser built for that format
   • Switching to the RE2 engine
8. Which Python function requires the entire string to match the pattern?
   • re.fullmatch
   • re.search
   • re.findall
   • re.sub