Don't know much about ruby, but I'm pretty sure that's how they're converting the numbers to strings.

I don't know what post you're answering to, but what you're saying is false:
['this is', 'a good example'].join(' ') => 'this is a good example'
'this is a good example'.split(' ') => ['this', 'is', 'a', 'good', 'example']
thus ['this is', 'a good example'].join(' ').split(' ') => ['this', 'is', 'a', 'good', 'example']