Mastering PHP 7

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:

<?phpclass 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 ...