PHP 객체 지향의 추상 클래스, 객체 인터페이스, 인스턴스 및 계약 프로그래밍 튜토리얼

abstract class AbstractClass
{
    code...
}

abstract public function prototypeName($protoParam);

<?php
abstract class Car
{    
    abstract function getMaxSpeend();
}
class Roadster extends Car
{
    public $Speend;
    public function SetSpeend($speend = 0)
    {
        $this->Speend = $speend;
    }
    public function getMaxSpeend()
    {
        return $this->Speend;
    }
}
class Street
{
    public $Cars ;
    public $SpeendLimit ;
    function construct( $speendLimit = 200)
    {
        $this -> SpeendLimit = $speendLimit;
        $this -> Cars = array();
    }
    protected function IsStreetLegal($car)
    {
        if ($car->getMaxSpeend() < $this -> SpeendLimit)
        {
            return true;
        }
        else
        {
            return false;
        }
    }
    public function AddCar($car)
    {
        if($this->IsStreetLegal($car))
        {
            echo &#39;The Car was allowed on the road.&#39;;
            $this->Cars[] = $car;
        }
        else
        {
            echo &#39;The Car is too fast and was not allowed on the road.&#39;;
        }
    }
}
$Porsche911 = new Roadster();
$Porsche911->SetSpeend(340);
$FuWaiStreet = new Street(80);
$FuWaiStreet->AddCar($Porsche911);
/**
 *
 * @result
 * 
 * The Car is too fast and was not allowed on the road.[Finished in 0.1s]
 *
 */
?>

<?php
abstract class Car
{    
    abstract function SetSpeend($speend = 0);
}
interface ISpeendInfo
{
    function GetMaxSpeend();
}
class Roadster extends Car implements ISpeendInfo
{
    public $Speend;
    public function SetSpeend($speend = 0)
    {
        $this->Speend = $speend;
    }
    public function getMaxSpeend()
    {
        return $this->Speend;
    }
}
class Street
{
    public $Cars ;
    public $SpeendLimit ;
    function construct( $speendLimit = 200)
    {
        $this -> SpeendLimit = $speendLimit;
        $this -> Cars = array();
    }
    protected function IsStreetLegal($car)
    {
        if ($car->getMaxSpeend() < $this -> SpeendLimit)
        {
            return true;
        }
        else
        {
            return false;
        }
    }
    public function AddCar($car)
    {
        if($this->IsStreetLegal($car))
        {
            echo &#39;The Car was allowed on the road.&#39;;
            $this->Cars[] = $car;
        }
        else
        {
            echo &#39;The Car is too fast and was not allowed on the road.&#39;;
        }
    }
}
$Porsche911 = new Roadster();
$Porsche911->SetSpeend(340);
$FuWaiStreet = new Street(80);
$FuWaiStreet->AddCar($Porsche911);
/**
 *
 * @result
 * 
 * The Car is too fast and was not allowed on the road.[Finished in 0.1s]
 *
 */
?>

echo $Porsche911 instanceof Car;
//result：1
echo $Porsche911 instanceof ISpeendInfo;
//result：1