php - 我的对象包含自身的多个实例，我应该担心吗？

Question

我有两个类，Quiz 和 Question:

class Quiz()
{

    public $quiz_id;
    public $quiz_name;

    // Arrays of objects
    public $questions;
    public $personalities;

    function __construct($quiz_id)
    {
        // Sets the basic data of the quiz
        $this->quiz_id = $quiz_id;
        $this->quiz_name = $quiz_name_from_db;
    }

    function LoadQuestions()
    {
        // Get question ids from database

        // Blank array to add questions to 
        $array_of_question_objects = array();

        foreach ($question_from_db AS $question_info)
        {

            // Create Question object, passing this Quiz object 
            $question_object = new Question($question_info["question_id"], $this);

            // Add the question to the array
            $array_of_question_objects += $question_object;

        }

        // Set the array within the Quiz object
        $this->questions = $array_of_question_objects;
    }

    function LoadPersonalities()
    {
        $this->personalities = $array_of_personalty_objects;
    }
}

class Question()
{

    public $question;

    // Quiz object within the question for access to personalities and quiz type
    private $quiz_object;

    function __construct($question_id, $quiz_object)
    {
        // Set the quiz object within the question
        $this->quiz_object;

        // Load the question information from the database and set the values of the class
        $this->question = $question_from_database;
    }


    function ShowQuestion()
    {
        // Show a question on the page and also
        // Loop through all of the personalities

        echo "<div id="question">";


        if ($quiz_object->quiz_type == "personality")
        {
            foreach ($quiz_object->personalities AS $quiz_personality)
            {

                // Show each personality
                echo $quiz_personality;
            }
        }
    }
}

如您所见，我需要让我的 Question 对象访问我的 Quiz 对象值:$quiz_type 和 $personalities。

如果我想加载所有问题及其可能的性格结果，我将使用以下代码:

$quiz_id = 1;

// Create a quiz object
$quiz_object = new Quiz($quiz_id);

// Load the questions in to the Quiz object
$quiz_object->LoadQuestions();

// Load all of the personalities
$quiz_object->LoadPersonalities();

// Show the questions
foreach ($quiz_object->questions AS $question)
{
    // Show the question
    $question->ShowQuestion();
}

如果我只想显示一个问题(以及所有个性信息)，我可以使用以下代码:

$quiz_id = 1;
$question_id = 40;

// Create a quiz object
$quiz_object = new Quiz($quiz_id);

// Load all of the personalities for the quiz object
$quiz_object->LoadPersonalities();

// Load the question as an object
$question_object = new Question($question_id, $quiz_object);

// Show the HTML for the question
$question_object->ShowQuestion();

我担心我的每个问题对象都需要来自测验对象的信息才能运行。

当我将所有问题对象加载到我的测验中时(使用 $quiz_object->LoadQuestions)，我的测验对象基本上包含问题信息以及多次自身的实例测验的问题。

所以有点像

Quiz_object {

Question_object:
{
    question information
    instance of `Quiz_object`
}

Question_object:
{
    question information
    instance of `Quiz_object`
}

Question_object:
{
    question information
    instance of `Quiz_object`
}

Question_object:
{
    question information
    instance of `Quiz_object`
}

Question_object:
{
    question information
    instance of `Quiz_object`
}

}

所以我的 Quiz 对象在对象中被复制了多次。

我应该关心这个，还是 PHP 处理我传递的实例只是作为对对象的“引用”？

Answer 1

即使您将相同 测验实例分配给多个变量，这也一定不是问题，但完全没问题。

因为您在这里只有一个实例，并且每个变量都是访问那个实例的一种方式，所以在您的示例中，问题知道它们属于哪个测验的。

在您的设计中，问题需要知道它们属于哪个测验，这就是您所需要的，因此它是普遍适用的。

这是一个标准的 1:n 关系:

   1:n

quiz:questions

注意将关系数量保持在应用程序运行所需的最低限度。