I wish more people understood this. Lol Especially for beginners, seeing one line of code without anyting meaningful just makes no sense to me.

shorter code != better code

IMHO This is readable but bad performance wise.
IndexOf & lastIndexOf iterate over all elements in the array. Therefore, this will have a quadratic time look-up since the function is looking at a every index in the array 3 times.

Nice, more performant than my answer.

This was how I came up with it too!

Same solution here, but isn't using too many lines?

To be fair, I think this is the most comprehensible solution.

Its just the most simple syntax, most beginners like myself use that

Oh wow, my solution is just like yours.

well done!

1. modifying an argument is not a good practice
2. sort() works in place, no need to assign it to "numbers" once again
3. it's a needless waste of resources, why rearragne the whole array if the stray number can be at the beginning?

nice

Took me a while to get this answer. While it is very clever, I don't see how this is anywhere close to a best practice.

Love it!

You used sort. Not that much faster.

There are simple O(n) solutions. They actually are much faster.