What is the difference between a greedy and a non-greedy match in regular expressions?
Assesses fundamental understanding of JavaScript conventions, runtime behavior, and memory/performance considerations.
Hiring managers look for precision, avoidance of ambiguous jargon, and ability to explain trade-offs under real production conditions.
In regular expressions, a greedy match will match as much as possible while still allowing the overall pattern to match. A non-greedy match, on the other hand, will match as little as possible while still allowing the overall pattern to match. Greedy matching is the default behavior in most regex engines. To make a match non-greedy, you can use the question mark (?) after the quantifier. For example, the regular expression ".\*?" will match as few characters as possible.
Candidate Response Strategy & Interview Tips
- Start with a concise one-sentence summary: Deliver a direct, confident answer first before expanding into nuances.
- Demonstrate real-world trade-offs: Discuss where this approach excels and when you would avoid it in production systems.
- Discuss complexity & edge cases: Proactively explain time/space complexity or boundary conditions (null values, scale limits).
- Prepare for interviewer follow-ups: Technical hiring panels frequently probe deeper into concurrency, backward compatibility, or alternative libraries.