[PHP-DOC] Bug #16245 Updated: Static variables into class member funtions have wrong scope From: hholzgra <email protected>
Date: 06/17/02

 ID: 16245
 Updated by: hholzgra <email protected>
 Reported By: flying <email protected>
-Status: Open
+Status: Bogus
 Bug Type: Documentation problem
 Operating System: Windows 2000 Server
 PHP Version: 4.0.6
 New Comment:

Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to report
a bug at http://bugs.php.net/how-to-report.php

Previous Comments:
------------------------------------------------------------------------

[2002-03-24 14:26:07] flying <email protected>

> I guess this is expected behaviour.

 I can't agree with it. If there is two separate instances of a class -
they must have no common variables, but they have.

> Reclassified as a documentation problem.
> (BTW you can use global $cnt to overcome this problem)

 No, problem can be solved by having member variable instead of static.

------------------------------------------------------------------------

[2002-03-24 14:22:08] sander <email protected>

I guess this is expected behaviour.
Reclassified as a documentation problem.
(BTW you can use global $cnt to overcome this problem)

------------------------------------------------------------------------

[2002-03-24 11:28:51] flying <email protected>

 Static variables inside member functions of a classes have wrong
scope. They should belong to each instance of a class, like normal
class properties, but they're belong to class definition instead and,
therefore, shared between every instance of this class. It makes static
variables unusable into class member variables.
 Here is an example:

// Define class
class A
{
    var $id = null;

    function A($id)
    {
        $this->id = $id;
    }

    function func()
    {
// Here we have counter into static variable
        static $cnt;
        if (!$cnt)
            $cnt = 0;
// Show counter value and ID of a class instance
        echo $this->id.": ".($cnt++)."\n";
    }
};

// Create 2 instances of our class with different IDs
$a = new A('A');
$b = new A('B');
// Call method of each class instance twice and see,
// what will happen
$a->func();
$b->func();
$a->func();
$b->func();

Expected results:
-----------------
A: 0
B: 0
A: 1
B: 1

Actual results:
---------------
A: 0
B: 1
A: 2
B: 3

------------------------------------------------------------------------ 

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Edit this bug report at http://bugs.php.net/?id=16245&edit=1