为什么Class扩展不会获得私有变量

Question

The following code does not produce the output with the name Jock. I suspect because in the class Animal the $name is private, but the construct is public so should the subclass not be able to get the $name from the construct. I do not want to make $name public.

class Animal{
    private $name;
    public function __construct($name) {
        $this->name = $name;
    }
    public function Greet(){
        echo "Hello, I'm some sort of animal and my name is ", $this->name ;
    }
}

 class Dog extends Animal{
     private $type;

     public function __construct($name,$type) {
         $this->type = $type;
           parent::__construct($name);

     }
     public function Greet(){
         echo "Hello, I'm a ", $this->type, " and my name is ", $this->name;
     }
 }
   $dog2 = new Dog('Jock','dog');
   $dog2->Greet();

Answer 1

the private variable only accessed inside the same class, you need to use protected for the name variable in class Animal.

class Animal{
    protected  $name;
    public function __construct($name) {
        $this->name = $name;
    }
    public function Greet(){
     echo "Hello, I'm some sort of animal and my name is ", $this->name;
  }
}
class Dog extends Animal{
 private $type;

 public function __construct($name,$type) {
     $this->type = $type;
       parent::__construct($name);

 }
 public function Greet(){
     echo "Hello, I'm a ", $this->type, " and my name is ", $this->name;
  }
 }
$dog2 = new Dog('Jock','dog');
$dog2->Greet();