PHP:如何使用::而不是\来访问命名空间类？

namespace MyNamespace;

class MyClass {
    public function example() {
        echo "Hello from MyClass!";
    }
}

namespace AnotherNamespace;

class AnotherClass {
    public function anotherExample() {
        echo "Hello from AnotherClass!";
    }
}

$myClassObject = new MyNamespace\MyClass();
$anotherClassObject = new AnotherNamespace\AnotherClass();

$myClassObject->example();
$anotherClassObject->anotherExample();

namespace MyNamespace;

class MyClass {
    public function example() {
        echo "Hello from MyClass!";
    }
}

namespace AnotherNamespace;

class AnotherClass {
    public function anotherExample() {
        echo "Hello from AnotherClass!";
    }
}

$myClassObject = new \MyNamespace\MyClass();
$anotherClassObject = new \AnotherNamespace\AnotherClass();

$myClassObject->example();
$anotherClassObject->anotherExample();