Format a 10-digit phone number string into the pattern (XXX) XXX-XXXX. Return the original string if it's not exactly 10 digits.

Examples:

Input: phoneNumber = "1234567890" Output: "(123) 456-7890" Explanation: Formatted 10-digit number with area code in parentheses and hyphen Input: phoneNumber = "123456789" Output: "123456789" Explanation: Not 10 digits, so returned unchanged
Apex Code Editor

Welcome to Lightning Challenge!

How It Works

  • • Write your solution in the code editor
  • • Connect your Salesforce org to test
  • • Submit to check if your solution passes
  • • Use hints if you get stuck

Contest Alert

🏆 #CodeEveryDay July 2026

Contest runs July 1 - 31. Complete challenges to climb the leaderboard!

Only the 31 daily challenges shown during this contest count toward points. Earlier dailies don't carry over.

Wally can't hear you

Please sign in to access the AI Assistant

Sign In