Using __isset()

The __isset() magic method is triggered by calling the isset() or empty() language constructs on inaccessible properties. The method accepts a single parameter, as per the following synopsis:

public bool __isset(string $name)

The $name argument is the name of the property being interacted with.

Let's take a look at the following object context example:

<?php

class User
{
  private $data = [
    'name' => 'John',
    'age' => 34,
  ];

  public function __isset($name)
  {
    if (array_key_exists($name, $this->data)) {
      return true;
    }

    return false;
  }
}

$user = new User();

var_dump(isset($user->name));

The User class defines a single protected array property called $data, and a magic __isset() method. The current method's inner workings simply do a name lookup against the $data array key names and return true if the key is found in the array, otherwise, false. The resulting output of the example is bool(true).

The Magento platform provides an interesting...