Type hinting - specify an array of objects

Question

Is there a way to specify the argument type as an array? Assume if I have a class named foo:

class Foo {}

And I have a function that accepts that class type as an argument:

function getFoo(Foo $f) {}

I am getting an error when I pass in the array:

Catchable fatal error: Argument 1 passed to getFoo() must be an instance of Foo, array given

Is there a way to solve this?

Answer 1

To know that you are with the  with "Array of Foo" and you want to ensure methods receive "Array of Foo", then use this:

class ArrayOfFoo extends \ArrayObject {
    public function offsetSet($key, $val) {
        if ($val instanceof Foo) {
            return parent::offsetSet($key, $val);
        }
        throw new \InvalidArgumentException('Value must be a Foo');
    }
}

Then:

function workWithFoo(ArrayOfFoo $foos) {
    foreach ($foos as $foo) {
        // etc.
    }
}

$foos = new ArrayOfFoos();
$foos[] = new Foo();
workWithFoo($foos);

You have to define a new "type" of "array of foo", then pass that "type" around using type hinting protection.

I hope this helps you.