And is correct that way because inputs "... are always lowercase strings, and that each has at least two letters.". If that was not the case and arbitrary inputs would be allowed we'd also need checks for null and lengths in order to avoid NullPointerException and IndexOutOfBoundsException or alike.

it work only if cases are equal

I would rather have more spaces to increase the readability of the code, but it's okay

Very efficient

Such an answer should not pass:

https://www.codewars.com/kata/reviews/5ba2f4cb19d12a69d50002af/groups/5ca95aec613d5d0001175036

Generate an array of random length with random ints, while ensuring that it contains exactly one (2,n,4) tuple at a randomized location. Use your "model" solution to generate the correct answer, and then do an assertEquals to compare yours with the user's answer. Throw this in a loop for a few dozen iterations.

The point of randomized testing is to prevent hardcoded answers, so that the user has to actually solve the problem. Your kata should have one or more fixed tests methods, generally pulled from the sample tests, and any edge cases. Then at least one random tests method to block cheating.

How do I set up random tests?

Thank you telling me. I wouldn't hava noticed

Typo in initial method name Kata should be kata

When I said "read the Tutorial: creating your first kata article", I actually meant it. Creating trash katas (and what's worse - spamming them) is highly dicouraged, so please don't.

output a to the power of b

No, you should return.

a and b will be whole positive numbers

It doesn't matter whether a is positive or negative. And if b was negative, the result would simply be truncated to 0.

This is my first kata I have created so I'm sorry if it terrible

Then take a look at this article. And don't make any more bad katas.