# Copying of arrays

- Thread: https://externals.io/message/969
- Original archive: https://news-web.php.net/php.internals/969
- Started by Ilia A. on 2003-04-19T02:22:09+00:00
- Messages: 1
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## #969 — Ilia A. — 2003-04-19T02:22:09+00:00

URL: https://externals.io/message/969#969

Bug #23195 demonstrates an interesting  in the way arrays are copied in PHP.
If inside the code that depends on the position of the array the array is 
copied to another variable it's internal position gets reset. This, as the 
example below will show will cause an unterminated loop.

<?php
        $arr = array('a', 'b'); while (each($arr)) $arr2 = $arr;
?>

The source of the problem could be traced to zend_hash_copy(), which will 
always reset the internal pointer of the target array to the 'head' element. 
This can be remedied by setting the internal pointer of the new array to the 
same as the source array, which solves the problem (patch attached). Or we 
document this problem and tell people to assign values by reference if they 
need to assign an array, which is being traversed to another variable.

Ilia