How to check if variable is array?… or something array-like

Question

I want to use a foreach loop with a variable, but this variable can be many different types, NULL for example.

So before foreach

Answer 1

If you are using foreach inside a function and you are expecting an array or a Traversable object you can type hint that function with:

function myFunction(array $a)
function myFunction(Traversable)

If you are not using foreach inside a function or you are expecting both you can simply use this construct to check if you can iterate over the variable:

if (is_array($a) or ($a instanceof Traversable))