About this challenge
Reverse String is a easy algorithms coding challenge. It tests algorithmic thinking and complexity analysis — the kind of problem-solving that shows up constantly in technical interviews. Write your solution in the editor above, run it against the test cases, and get instant feedback — free, in your browser, no sign-up.
Show a hint & approach (spoiler)
Hint: Use two pointers — one at the start, one at the end — and swap until they meet in the middle.
Approach: Two-pointer swap is O(n/2) = O(n) time with O(1) space. Avoid .reverse() to learn the pattern.
Keep practicing
Browse all coding challenges, or build intuition for the underlying concepts with the algorithm visualizers and the developer cheatsheets.