how to use recursion for nested foreach with each key in array

Question

I have an array

$array = array(
        0 => array('a1', 'a2'),
        1 => array('b4', 'b3', 'b5'),
        2=> array('c1', 'c3'),
        3=> array('d2' , 'd5', 'd6')
);

I want to process the array as the program below :

$data= array();
$tmp = array();
foreach($array[0] as $arr0){
    $tmp[0]= $arr0;
    foreach($array[1] as $arr1){
        $tmp[1]= $arr1;
        foreach($array[2] as $arr2){
            $tmp[2]= $arr2;
            foreach($array[3] as $arr3){
                $tmp[3]= $arr3;
                $data[]= $tmp;
            }
        }
    }
}

print_r($data);

So how to use recursion for this program ?.

You just want to print the array keys? your question isn't clear to me. — Pedro Lobito, May 21 '17 at 13:20
Learning recursion works best when you attempt to do it, fail and have a specific question instead of a request for someone to do it for you. `:)` — Jared Farrish, May 21 '17 at 13:24
You posted only a 2-dimensional array, why would you iterate it 4 layers deep? — ccKep, May 21 '17 at 13:24
@ccKep - Look at it again, the first loop may be unnecessary or produce unexpected results. — Jared Farrish, May 21 '17 at 13:25
i want to get value "$data" after the programe complete process. but i want to convert the program into recursion. — kaito kid, May 21 '17 at 13:27
Possible duplicate of [All possible combinations in array - recursion?](http://stackoverflow.com/questions/21556945/all-possible-combinations-in-array-recursion) — ccKep, May 21 '17 at 13:29

score 1 · Answer 1 · answered May 21 '17 at 13:37

1

Try this, check the live demo.

$result = [];
$temp = [];
foreach($array as $arr)
{
    foreach($arr as $v)
    {
        if($result == [])
          $temp[] = [$v];
        else{
        foreach($result as $val)
        {
          $val [] = $v;
          $temp[] = $val;
        }
        }
    }
    $result = $temp;
    $temp = [];
}
print_r($result);

answered May 21 '17 at 13:37

LF00

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it's just the order isuse. and my implementation is short of code than [your order implementation](https://eval.in/802254). If it helps please accept it and upvote it – LF00 May 21 '17 at 14:05
While this code snippet may solve the question, [including an explanation](http://meta.stackexchange.com/questions/114762/explaining-entirely-code-based-answers) really helps to improve the quality of your post. Remember that you are answering the question for readers in the future, and those people might not know the reasons for your code suggestion. Please also try not to crowd your code with explanatory comments, this reduces the readability of both the code and the explanations! – Rizier123 May 21 '17 at 16:15

how to use recursion for nested foreach with each key in array

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