Hi,

Below you will find a piece of code which is intended to make two two-dimensional arrays: $aa and $bb. In fact, both arrays should be the same, as far as I can see. It seems however that the unset($b_nw) is crucial. 

As far as I understood from the documentation, an assignement with an arrray on the right-hand side should perfrom a copy of the array. My assumption is that the same should be true with a reference to an array, because there is no way to distinguish between them. So please have a look at my code and tell me when you need more information, or if I misunderstood something.


The code:

<?php
   $a=array(0);
   $b=array(0);
   $aa=array(&$a);
   $bb=array(&$b);
   for ($i=1; $i<3; $i++) {
     $a_nw=$a;
     $a_nw[]=$i;
     $aa[]=&$a_nw;
     $b_nw=$b;
     $b_nw[]=$i;
     $bb[]=&$b_nw;
     unset($b_nw);
   }
   echo "<b>aa: </b>";
   print_r($aa);
   echo "<br>\n";
   echo "<b>bb: </b>";
   print_r($bb);
   echo "<br>\n";
?>


The output:
aa: Array ( [0] => Array ( [0] => 0 ) [1] => Array ( [0] => 0 [1] => 2 ) [2] => Array ( [0] => 0 [1] => 2 ) ) 
bb: Array ( [0] => Array ( [0] => 0 ) [1] => Array ( [0] => 0 [1] => 1 ) [2] => Array ( [0] => 0 [1] => 2 ) ) 

Note that $aa[1] != $bb[1], which is unexepected ($bb[1] is the correct value, I think).

Thanks,

Marco.