Question

在此示例中, 我如何访问对象 $containerObj 中的属性? 对象 gang ContainerID () 方法中的属性 $containerObj- gt;bar , 或者至少找到一个指针到 $containerObj ?

class Foo {
  public $id = 123;
}

class Bar {
  function getContainerID() {
    ... //**From here how can I can access the property in the container class Foo?**
  }
}

$containerObj = new Foo();
$containerObj->bar = new Bar();

echo $containerObj->bar->getContainerID();

Answer 1

您不能以这种方式这样做。对于某一类的引用可以指定给多个变量, 例如 :

$bar = new Bar();
$container = new Foo();
$container->bar = $bar;
$container2 = new Foo();
$container2->bar = $bar;

现在应该归还哪个Foo集装箱?

d 最好改变方向,使容器了解指定的物体(反之亦然):

class Foo {
    public $id = 23;
    private $bar;
    public function setBar(Bar $bar) {
        $this->bar = $bar;
        $bar->setContainer($this);
    }
}
class Bar {
    private $container;
    public function setContainer($container) {
        $this->container = $container;
    }
    public function getContainerId() {
        return $this->container->id;
    }
}
$bar = new Bar();
$foo = new Foo();
$foo->setBar($bar);
echo $bar->getContainerId();

友情链接