If you are working with basic primitive values like strings, integers, and arrays,

and you use PHP 7+ and you can't use polymorphism but you still feel the need to

type-check, you should consider

or strict mode. It provides you with static typing on top of standard PHP syntax.

The problem with manually type-checking is that doing it will require so much

extra verbiage that the faux "type-safety" you get doesn't make up for the lost