PHP Car::getStatus方法代码示例

    }
    public function getStatus()
    {
        $this->doStuff();
        // can call the protected function
        return $this->status;
    }
    function __construct($c = 'blue')
    {
        $this->color = $c;
    }
}
// create an instance of Car class
$myCar = new Car();
echo '<p>' . $myCar->color . '</p>';
echo '<p>' . $myCar->getStatus() . '</p>';
echo '<p>' . $myCar->doMoreStuff() . '</p>';
// works
echo '<p>' . $myCar->flag . '</p>';
// doesn't work
echo '<p>' . $myCar::$flag . '</p>';
// works
echo '<p>' . Car::$flag . '</p>';
// must reference the class::property
class SUV extends Car
{
    public $has4WD = 'yes';
}
$newCar = new SUV('black');
echo '<p>' . $newCar->color . '</p>';
echo '<p>' . $newCar->getStatus() . '</p>';

 public function getStatus()
 {
     // child classes can still access parent methods using parent::
     return parent::getStatus();
 }

    var $model = '';
    protected $status = 'off';
    function startEngine()
    {
        $this->status = 'running';
        // if engine were an object inside the Car object
        //$this->engine->status = 'running';
    }
    function getStatus()
    {
        return $this->status;
    }
}
$myCar = new Car();
$myCar->color = 'black';
$myCar->make = 'Mercedes';
$myCar->model = '725L';
echo "<p>My car will be a {$myCar->color} {$myCar->make} {$myCar->model}.</p>";
//$myCar->status = 'running'; // doesn't work because $status is protected
echo '<p>Current car status: ' . $myCar->getStatus() . '.</p>';
$myCar->startEngine();
// start 'er up
echo '<p>Current car status: ' . $myCar->getStatus() . '.</p>';
$yourCar = new Car();
echo '<p>Your car\'s status: ' . $yourCar->getStatus() . '.</p>';
// Accessing sub-objects might look something like this:
//$myCar->engine->start();
?>

</body>
</html>

    static $doesHave4WD = true;
    public function getStatus2()
    {
        return $this->status;
    }
    // static members are accessed directly from the class using ::
    // they are not accessible from class instances
    static function has4WD()
    {
        // can't use $this in a static method because it's not associated
        // with an instance
        //return $this->has4WD;
        // we also can't access non-static members directly from the class
        //return SUV::has4WD;
        // note that the static variable has the $ in the name
        return SUV::$doesHave4WD;
    }
}
$yourCar = new Car(array('make' => 'Cadillac', 'model' => 'El Dorado', 'color' => 'pearl'));
$myCar = new SUV();
echo '<p>Your car color is ' . $yourCar->color . '</p>';
echo '<p>Your car ' . (isset($yourCar->has4WD) && $yourCar->has4WD ? 'has' : 'does not have') . ' four-wheel drive.</p>';
echo '<p>My car ' . (isset($myCar->has4WD) && $myCar->has4WD ? 'has' : 'does not have') . ' four-wheel drive.</p>';
echo '<p>Your car status is ' . $yourCar->getStatus() . '</p>';
echo '<p>My car status is ' . $myCar->getStatus() . '</p>';
// generates a warning because $status is private
echo '<p>My car status is ' . $myCar->getStatus2() . '</p>';
$myCar->has4WD();
// can't access static properties
echo SUV::has4WD();
// access the static member directly from the class

class Car
{
    // variables inside a class are called properties or attributes
    public $make = null;
    public $model = null;
    public $color = null;
    protected $status = 'off';
    // functions inside a class are called methods
    public function setStatus($value)
    {
        // '$this' refers to the current instance
        $this->status = $value;
    }
    public function getStatus()
    {
        return $this->status;
    }
}
// we create instances (actual objects) of a class using 'new'
$yourCar = new Car();
$myCar = new Car();
// use the '->' operator to access an object's members
$yourCar->color = 'red';
$yourCar->color = 'blue';
echo '<p>Your car color is ' . $yourCar->color . '.</p>';
//echo $yourCar->status;
echo '<p>Your car status is ' . $yourCar->getStatus() . '</p>';
$yourCar->setStatus('running');
echo '<p>Your car status is ' . $yourCar->getStatus() . '</p>';
echo '<p>My car status is ' . $myCar->getStatus() . '</p>';