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Regex Roulette · #28 · 2026-05-02

Match positive integers (no zero, no negatives, no decimals)

Difficulty 1/3

How to play

Write a regex that matches all green strings and rejects all red strings. Live feedback shows which strings pass. Shorter patterns score better.

Must match

  • 1 — not yet evaluated
  • 42 — not yet evaluated
  • 100 — not yet evaluated
  • 999 — not yet evaluated

Must not match

  • 0 — not yet evaluated
  • -1 — not yet evaluated
  • 3.14 — not yet evaluated
  • 0042 — not yet evaluated
  • +5 — not yet evaluated

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Pattern body only — slashes and flags (e.g. /g, /i) aren't part of the input.

0/200 chars

Type a regex that matches all green strings and rejects all red strings · Back to hub