This kata is a candidate for retirement as it relies on contraints which are not enforced well, and are very difficult to enforce. Please join the discussion and share your opinion on whether this kata should be kept, or retired: https://github.com/codewars/content-issues/issues/167.

Id just like to ask what exactly temporary arrays and objects are

No random tests

Node 12.x should be enabled.

Please point out that the JOSN.stringify is not allowed also.

I think the kata description should be updated to say no regex. I originally wrote a solution using String.prototype.replace (which isn't an Object or Array prototype method) only to find on submission that replace isn't allowed.

I enjoyed this kata, otherwise.

You are NOT allowed to use any temporary arrays or objects.

I'm not entirely sure what it means exactly by not allowed to use temporary objects. Am I allowed to use temporary vars to store Number? (e.g. let x = array[i - 1])

However, you can still use the methods of an array, and can't resolve with the Regex.

arr['slice'](i, 1)[0]
arr['re' + 'du' +'ce'](i, 1)[0]

You can use monkey patching method to built-in objects.

I posted to the gist, and you can use it.