why class attribute assign by reference doesn't work?

class c{
    public $myV = &$_GET;
}

it 开发者_JAVA技巧gives me error :(

if i do a plain simple:

$myV = &$_GET;

it works

You cannot even do this:

public $x = $y;

From the manual:

This declaration may include an initialization, but this initialization must be a constant value--that is, it must be able to be evaluated at compile time and must not depend on run-time information in order to be evaluated.

To get around this, just set it in the __construct function.

public function __construct()
{
  $this->myV = &$_GET;
}

... but this initialization must be a constant value--that is, it must be able to be evaluated at compile time and must not depend on run-time information in order to be evaluated.

from php.net : Properties

You can define this dependency in a constructor though.

Try this:

class c {
    public $myV;

    function c() {
        $this->myV = &$_GET;
    }
}

You cannot assign variables to fields before a class is instantiated. This way, your variable will be set when an object is made from your class.

You can achieve a similar effect like:

class c{
   public $myV;
   function __construct() { $this->myV = &$_GET; }
}