PHP Duck Sample - Head First - Design Patterns - Chapter One

Question

This is the first question I ask from many others to come.

Someone here might call me crazy because I\'m following the mentioned book in the question\'s Title using

Answer 1

The reason you are seeing Quack!
output is because of this:

class Quack implements QuackBehavior {

    public function quack() {
        echo 'Quack!
';
    }
}

Here's your problem: If you simply run new Quack(); the quack() method is automatically being executed by php as a constructor because it is the same name as your class. -- I see you referenced Java in your question, so this shouldn't be a foreign concept to you.

new Quack(); // => Quack!

---

A potentially better way

color} wings\n";
  }

  public function quack(){
    echo "I'm quacking\n";
  }

  public function swim(){
    echo "I'm swimming\n";
  }
}

class Mallard extends Duck {

  public function __construct(){
    $this->color = "green";
  }

  public function quack(){
    echo "My quack sounds more like a honk\n";
  }
}

$m = new Mallard();
$m->fly();
$m->quack();
$m->swim();

?>

Output

I'm flying with my green wings
My quack sounds more like a honk
I'm swimming