如何通过在 PHP 中通过引用传递变量来存储变量？

Question

我正在努力掌握 PHP 7+ 为 Conflict Resolution. I also want to make a dynamic call to save() in my design, which will take in a argument by reference 引入的 OOP 概念。

为了在我将此添加添加到我的框架之前测试这个概念，我想尝试简单地输出变量的 zval 的基础知识。

我目前的特质是这样的：

trait Singleton {
    # Holds Parent Instance
    private static  $_instance;
    # Holds Current zval
    private         $_arg;

    # No Direct Need For This Other Than Stopping Call To new Class
    private function __construct() {}

    # Singleton Design
    public static function getInstance() {
        return self::$_instance ?? (self::$_instance = new self());
    }

    # Store a reference of the variable to share the zval
    # If I set $row before I execute this method, and echo $arg
    # It holds the correct value, _arg is not saving this same value?
    public function bindArg(&$arg) { $this->_arg = $arg; }

    # Output the value of the stored reference if exists
    public function helloWorld() { echo $this->_arg ?? 'Did not exist.'; }
}

然后我创建了一个 class，它利用了 Singleton 特性。

final class Test {
    use \Singleton { helloWorld as public peekabo; }
}

我像这样传入了我想引用的变量，因为该方法需要变量的引用——它还不需要设置。

Test::getInstance()->bindArg($row);

我现在想模仿从数据库结果中循环遍历行的概念，这个概念是允许将 save() 方法添加到我的设计中，但首先要让基本概念起作用。

foreach(['Hello', ',', ' World'] as $row)
    Test::getInstance()->peekabo();

问题是，输出如下所示：

Did not exist.Did not exist.Did not exist.

我的预期输出如下：

Hello, World

如何将 zval 存储在我的 class 中以便以后在单独的方法中使用？

Demo for future viewers of this now working thanks to the answers

Demo of this working for a database concept like I explained in the question 这里：

"I now want to mimic the concept of looping through rows from a database result, the concept is to allow a save() method to be added to my design"

Answer 1

使用 public function bindArg(&$arg) { $this->_arg = &$arg; } 它适用于 PHP 7.3

如何通过在 PHP 中通过引用传递变量来存储变量？

How can I store a variable by passing it by reference in PHP?

php

oop

reference

pass-by-reference

traits