Find the index of a given element in a list. Return the index of the first occurrence of the element, or -1 if the element is not found.

Examples:

Input: numbers = [10, 20, 30, 40, 50], target = 30 Output: 2 Explanation: The element 30 is found at index 2 in the list Input: fruits = ['apple', 'banana', 'orange', 'banana'], target = 'banana' Output: 1 Explanation: The element 'banana' first occurs at index 1 in the list
Apex Code Editor
Sign in to Submit

Welcome to Lightning Challenge!

Create an Account

Sign up to track your progress, earn points, and compete with others. Your solutions will be saved automatically.

Create account

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 Feb 2026

Contest runs February 1 - 28. Complete challenges to climb the leaderboard!

Points are calculated for challenges completed during the contest period.