note 102761 added to function.shuffle

The function array_2D_permute published earlier is useful but buggy: when called more than once within the same script, it keeps all previous values in static $permuted_array, thus creating duplicates. The corrected version of the function makes use of the additional flag to differentiate between 1st(external) call of array_2D_permute and all subsequent(recursive, internal) calls.

<?php

# originally published http://uk.php.net/manual/en/function.shuffle.php#62840
# Takes a non-associative 1D (vector) array of items
#  and returns an array of arrays with each possible permutation
function array_2D_permute($items, $perms = array(), $isCalledRecursively = false) {
static $permuted_array;
	if(!$isCalledRecursively) $permuted_array = array();
    if (empty($items)) {
        $permuted_array[]=$perms;
    }  else {
        for ($i = count($items) - 1; $i >= 0; --$i) {
             $newitems = $items;
             $newperms = $perms;
             list($foo) = array_splice($newitems, $i, 1);
             array_unshift($newperms, $foo);
             array_2D_permute($newitems, $newperms, true);
         }
         return $permuted_array;
    }
}

// NB now that this bug has been corrected, both produced results will be identical
$arr=array("Architecture","Mexico");

$result1=array_2D_permute($arr);
print_r($result1);

$result2=array_2D_permute($arr);
print_r($result2);
?>
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Probable Submitter: 195.33.27.190
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Manual Page -- http://www.php.net/manual/en/function.shuffle.php
Edit        -- https://master.php.net/note/edit/102761
Del: integrated  -- https://master.php.net/note/delete/102761/integrated
Del: useless     -- https://master.php.net/note/delete/102761/useless
Del: bad code    -- https://master.php.net/note/delete/102761/bad+code
Del: spam        -- https://master.php.net/note/delete/102761/spam
Del: non-english -- https://master.php.net/note/delete/102761/non-english
Del: in docs     -- https://master.php.net/note/delete/102761/in+docs
Del: other reasons-- https://master.php.net/note/delete/102761
Reject      -- https://master.php.net/note/reject/102761
Search      -- https://master.php.net/manage/user-notes.php