PHP Reference to a static variable

Question

I'm not sure if this is possible at all in PHP but this is what I try to do. I have a static variable in my class that I want to have as a reference outside the class.

class Foo {

  protected static $bar=123;

  function GetReference() {

    return self::&$bar; // I want to return a reference to the static member variable.
  }

  function Magic() {

    self::$bar = "Magic";
  }
}

$Inst = new Foo;
$Ref = $Inst->GetReference();
print $Ref; // Prints 123
$Inst->DoMagic();
print $Ref; // Prints 'Magic'

Can someone confirm if this is possible at all or another solution to achieve the same result:

The variable must be static because class Foo is a base class and all derivates needs access to the same data.
HTML needs access to the class reference data, but not to be able to set it without a setter method because the class needs to know when the variable is set.

I guess it can always be solved with globals declared outside the class and some coding disciplines as an emergency solution.

// Thanks

[EDIT]
Yes, I use PHP 5.3.2

Why make a reference? In most cases it can be handled without a reference (for example, using explicit getters/setters). References make code which is rather difficult to debug (since side-effects in one piece of code can effect other pieces of code). Try to stay away from them unless absolutely necessary (which in my experience is seldom)... — ircmaxell
– ircmaxell, Commented Feb 15, 2011 at 13:44

DrDol · Accepted Answer · 2013-03-18 10:06:21Z

3

The PHP documentation provides a solution: Returning References

<?php
class foo {
    protected $value = 42;

    public function &getValue() {
        return $this->value;
    }
}

$obj = new foo;
$myValue = &$obj->getValue(); // $myValue is a reference to $obj->value, which is 42.
$obj->value = 2;
echo $myValue;

edited Mar 18, 2013 at 10:06

answered Feb 15, 2011 at 13:39

DrDol

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4 Comments

ajreal Over a year ago

if you make $value public, you can directly access that outside from the class

Max Kielland Over a year ago

+1v It works!!! I'm an old fashion C++ OOP, so I kept it protected :) I was googling high and low and never came across this. Well, guess I have to improve my search technique as well :D Thank you!

DrDol Over a year ago

ajreal that's correct. I updated the example. Now, it makes more sense.

ThorSummoner Over a year ago

I don't always need to lookup how to reference object variables, but when I do, i'm using PHP.

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