In the past, I was never fond of 'in_array' due to speed, but you have such little data that it really does not play into account. In PHP 5.4 they drastically improved 'in_array', so there goes my argument. In that case, code readability is king, (in my opinion), and yours is straight forward. @Kh99 has already covered the plugin option. So there you go...
I got nothing.
(Back to my own coding mess, at work, this was suppose to be a distraction for a few minutes.

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