How to find all possible order with array item

How to find all possible order with array item

Here is an array.
$item = array('A', 'B', 'C', 'D');

I want to list all possible orders in this array like:
A
A,B
A,B,C
A,B,C,D
A,C
A,C,D
A,C,B
...
B,A
B,A,C
....
How can I do that?

Solutions/Answers:

Answer 1:

The permutations you want to know can be accomplished through this algorithm and applying in a loop for the subsets.

Initialize the first permutation with <1 <2 …

while there exists a mobile integer

find the largest mobile integer k

swap k and the adjacent integer it is looking at

reverse the direction of all integers larger than k

Refer to this question for more info

Answer 2:

You can use this recursive function:

function recursive_permutations($items,$perms = array( ))
{
 static $list;
 if (empty($items)) {
  $list[] = join(',', $perms);
 } else {
  for ($i = count($items)-1;$i>=0;--$i) {
   $newitems = $items;
   $newperms = $perms;
   list($foo) = array_splice($newitems, $i, 1);
   array_unshift($newperms, $foo);
   recursive_permutations($newitems, $newperms);
  };
  return $list;
 };
}
$perms = recursive_permutations(array('A', 'B', 'C', 'D'));
echo '<pre>' . print_r($perms, true) . '</pre>';

References

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