minte9

learningjourney

Type Hinting

  code
class A
{
    public function test(B $b)
    {
        echo $b->var;
    }
}

class B
{
    public $var = "Hello World";
}

$a = new A();
$b = new B();

try {

    //$a->test($b); // Hello World

    $a->test("b");
        // Argument 1 passed to A::test() must be ...
        // an instance of B, string given

} catch (TypeError $e) {

    echo $e->getMessage();
}

  code
declare(strict_types=1); // Look Here

class A
{
    public function test(float $number)
    {
        return $number;
    }
}

try {

    $obj = new A();

    $no = (String) 10; // Look Here

    echo $obj->test($no);

} catch (TypeError $e) {

    echo $e->getMessage();
        // Argument 1 passed to A::test()
        // must be of the type float, string given
}