They are not disabled

Hope you didn't hold your breath. You'd be blue in the face by now ..

Why not? According to the Wikipedia definition, it is. ( Convexity is promised nowhere. )

Closing.

This kata is from a time when Example Tests were a luxury. (As were random tests.)

I believe the original author was trying to point out the distinction between odd index and odd position. For a zero-based array, elements at even position are oddly indexed. He is not wrong about this, but it was confusingly worded. I've rewritten the 'note' section to hopefully make it more clear. It makes sense to me as written now, but if you still think it is poorly worded, please let me know and I'll try again.

7, max 6kyu.

Either the function returned something that is not a number, or the function did not return anything.

your for loop doesn't even start

It's now available in JS and Java.

Ok, should be fixed again... sorry for the delay;-)

Itˋs changed again - but not from my side, saw some new changes... Did you do this at same time?

Should be fixed now, see my other comment;-)...

the first letter is position 0