Question

In PHP, if you return a reference to a protected/private property to a class outside the scope of the property does the reference override the scope?

e.g.

class foo {   protected bar = array();   getBar()   {     return &bar;   }  }  class foo2 {   blip = new foo().getBar(); // i know this isn't php } 

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Is this correct and is the array bar being passed by reference?

Answer 1

Well, your sample code is not PHP, but yes, if you return a reference to a protected variable, you can use that reference to modify the data outside of the class’s scope. Here’s an example:

<?php class foo {   protected $bar;    public function __construct()   {     $this->bar = array();   }    public function &getBar()   {     return $this->bar;   } }  class foo2 {    var $barReference;   var $fooInstance;    public function __construct()   {     $this->fooInstance = new foo();     $this->barReference = &$this->fooInstance->getBar();   } } $testObj = new foo2(); $testObj->barReference[] = 'apple'; $testObj->barReference[] = 'peanut'; ?> <h1>Reference</h1> <pre><?php print_r($testObj->barReference) ?></pre> <h1>Object</h1> <pre><?php print_r($testObj->fooInstance) ?></pre> 

When this code is executed, the print_r() results will show that the data stored in $testObj->fooInstance has been modified using the reference stored in $testObj->barReference. However, the catch is that the function must be defined as returning by reference, AND the call must also request a reference. You need them both! Here’s the relevant page out of the PHP manual on that:

http://www.php.net/manual/en/language.references.return.php