Problem with references

[jstaerk]

Hi there.

I've attached a little sample I don't understand:
myC1 is constructed, that constructs myC2 in $this->theC2, which changes myC1's greeting to "bah". Then, $test->theC2->something(); should change myC1's greeting to "hulla", and finally, the greeting is printed.

Why does this sourcecode print "bah"?

<?

class myC1
{
  var
    $greeting;
  var  $theC2;
  function sayHello()
  {
      echo $this->greeting;
  }
  function myC1()
  {
      $this->greeting="Howdy";
      $this->theC2=new myC2($this);
  }



}

class myC2
{
  var $owner;
  function myC2(&$owner)
  {
    $this->owner=&$owner;
    $this->owner->greeting="bah";
  }
  function something()
  {
    $this->owner->greeting="hulla";
    // This is supposed to change myC1's greeting to hulla, overwriting "bah".
  }
 }


$test=new myC1();
$test->theC2->something();
$test->sayHello();

?>

[swr]

Try this at the end:

echo $test->greeting;
echo $test->theC2->owner->greeting;

Two different results. $test and $test->C2->owner are different instances. The reason is here:

$test=new myC1(); 

When that constructs theC2 the product of the "new" gets set as owner, but the assignment creates a clone your myC1, giving you a different instance than what was given to theC2.

This fixes it:

$test =& new myC1(); 

[jstaerk]

Hi SWR,

Thanks for that -- it solved the problem in a very aestetic way. Of course the snipped was just the reproduction of a shortcoming in a bigger system.

So, THANKS very, very much.