( at least JS, Haskell )

a function that removes the spaces from the values

This is not tested. In fact, the description seems not to specify the task at all.

This kata is a subject to deduplication process here: https://github.com/codewars/content-issues/issues/189.
Please join the discussion to help us identify duplicate kata and retire them.

C++ Translation

Needs random test cases

This is more of a test for whether you can figure out the author's intent than it is of your JS skills.

At the very least this needs more tests with varying insertions. Not a single hard-coded test.

I found very little value in this Kata. I'm not sure it is really that useful. What exactly are you trying to achieve with it?

There is a whitespace at the end of your string. This might be misleading...