Is there better way to transpose a PHP 2D array?

Question

According to the PHP Manual, calling array_map with a NULL callback causes it to perform a \"zip\" function, creating an array of arrays of paralle

Answer 1

Nope. That's the most elegant.

Answer 2

Update for PHP 5.6:

We can take advantage of PHP 5.6's "splat" operator to make this operation much, much cleaner with argument unpacking:

array_map(null, ...$array_of_arrays);

For example:

[1] boris> $arr2d = [ [1,2,3], ['a','b','c'] ];
// array(
//   0 => array(
//     0 => 1,
//     1 => 2,
//     2 => 3
//   ),
//   1 => array(
//     0 => 'a',
//     1 => 'b',
//     2 => 'c'
//   )
// )
[2] boris> array_map(null, ...$arr2d);
// array(
//   0 => array(
//     0 => 1,
//     1 => 'a'
//   ),
//   1 => array(
//     0 => 2,
//     1 => 'b'
//   ),
//   2 => array(
//     0 => 3,
//     1 => 'c'
//   )
// )

Answer 3

If you really want to avoid the array_merge, use array_unshift to prepend the NULL to the $array_of_arrays instead:

array_unshift($array_of_arrays, NULL);
call_user_func_array('array_map', $array_of_arrays);

Of course it is not a one-liner anymore :P