PHP：未定義偏移量：0，但不與dd（）

Question

我得到一個Undefined offset: 0與laravel錯誤。奇怪的是，當我dd()它，它出現了。

$ports = $container->getPorts(); 
    $ports = $ports[0]; 

這將返回Undefined offset: 0

當我dd()

$ports = $container->getPorts(); 
dd($ports[0]); 

Port {#336 
    #privatePort: 80 
    #publicPort: 32780 
    #type: "tcp" 
} 

全陣列：

array:1 [▼ 
    0 => Port {#336 ▼ 
    #privatePort: 80 
    #publicPort: 32780 
    #type: "tcp" 
    } 
] 

我收到此錯誤與泊塢窗的PHP SDK。任何人都知道發生了什麼？

全碼：

public function dockerContainers() 
{ 
    $docker = new \Docker\Docker(); 
    $containerManager = $docker->getContainerManager(); 
    $containers = $containerManager->findAll(); 

    $data = []; 
    $x=0; 
    foreach ($containers as $container) { 
     $ports = $container->getPorts(); 
     // dd($ports[0]); 
     $ports = $ports[0]; 
     $privatePort = $ports->getPrivatePort(); 
     $publicPort = $ports->getPublicPort(); 
     $data[$x++] = [ 
      'id' => $container->getId(), 
      'state' => $container->getState(), 
      'names' => $container->getNames(), 
      'image' => $container->getImage(), 
      'status' => $container->getStatus(), 
      'ports' => [ 
       'privatePort' => $privatePort, 
       'publicPort' => $publicPort 
      ] 
     ]; 
    } 

    return view('containers', [ 'containers' => $data ]); 
} 

Answer 1

這是因爲你container的一個沒有ports是用laravel collect()方法，讓您的數組集合對象很好的做法，那麼你可以使用可用的收集方法。 嘗試下面的代碼...

foreach ($containers as $container) { 
      //getting ports and making laravel collection object 
     $ports = collect($container->getPorts()); 
     if($ports->first()){ 
     $ports = $ports->first(); 
     $privatePort = $ports->getPrivatePort(); 
     $publicPort = $ports->getPublicPort(); 
     $data[$x++] = [ 
      'id' => $container->getId(), 
      'state' => $container->getState(), 
      'names' => $container->getNames(), 
      'image' => $container->getImage(), 
      'status' => $container->getStatus(), 
      'ports' => [ 
       'privatePort' => $privatePort, 
       'publicPort' => $publicPort 
      ] 
     ]; 
    } 
}