How to transpose and implode subarray data within a multidimensional array to create a flat output array?

Question

I don't have a specified number of subarrays, but my data structure can look like this:

array(("john","alex","tyler"),("1","2","3"),("brown","yellow","green"));

The above example has 3 subarrays, but the problem is this number can change.

As a final output I need, in this example, an array with 3 strings.

array("john,1,brown","alex,2,yellow","tyler,3,green");

I've tried to write this with functions, but couldn't find a solution.

Answer 1

The solution using call_user_func_array, array_map and array_merge functions:

$arr = [["john","alex","tyler"],["1","2","3"],["brown","yellow","green"]];

$groups = call_user_func_array("array_map", array_merge([null], $arr));
$result = array_map(function ($v) {
    return implode(",", $v);
}, $groups);

print_r($result);

The output:

Array
(
    [0] => john,1,brown
    [1] => alex,2,yellow
    [2] => tyler,3,green
)

http://php.net/manual/en/function.call-user-func-array.php