Because the second returns nil in this case:

If begin value is greater than the end, function should returns 0

I almost feel bad for voting:

Wording is ambiguous.

This this could be worded differently. Took me a while to understand the question.

cleaned up

The comment in the initial code says to move 1's to the end.

This is not even a waferthin wrapper around a native method. It is a native method.

This is not worthy of a kata. "Is the concept behind this kata novel?" Given that it's a native method, no, it's not in any way novel.

Please just unpublish this.

Description is awful.

Also, where are the random tests?

The kata did not specify whether to cut the size of the array down in-place, or leave the original array intact while returning a new array satisfying the property.

You never say you want to remove the n FIRST elements, maybe should you state it somewhere? And you don't actually need to cut the array, but jsut return a sub-array (which is not checked to be or not a subset of the initial array)... Quite messy and I don't think there's much to learn with that :/

How, first kata with adult innuendo I see on CW.

And it is not coming from me, I am getting senile T_T.

Btw, fixed the code template, cheers.

solved!

all sorted, thanks!