Combine 3 or more arrays (php)

Question

Quick example: array_1 = 1, 2, 3; array_2 = a, b, c and array_3 = white, red, blue.

I need an array like array_4 = ((1,a,white), (2,b,red), (3,c,blue)).

I hope I'm not being to confusing. Thanks in advance.

Answer 1

See http://stackoverflow.com/questions/1860490/interleaving-multiple-arrays-into-a-single-array

Answer 2

You mean something like Python's zip()? This will do:

$zipped = array_map(null, $array_1, $array_2, $array_3);

If you want a function that can do it with an arbitrary number of arrays, see: Is there a PHP function like Python's zip?

Answer 3

I guess you are looking for a one-liner? I can't provide that, but this is my attempt:

$array_4=array();
for($i = 0 ; $i<count($array_1) ; ++$i) {
  $array_4[$i] = array($array_1[$i], $array_2[$i], $array_3[$i]);
}

This code of course assumes that all input arrays have the same lengths.

If you have more than 3 input arrays I would put them all in an array and foreach over it:

$all_arrays = array($aray_1, $array_2, ...);
$output_array=array();
for($i = 0 ; $i<count($array_1) ; ++$i) {
  $output_array[$i] = array();
  foreach($all_arrays as $input_array) {
    $output_array[$i][] = $input_array[$i];
  }
}

Answer 4

I think the easiest way, without using a bunch of array_X functions would be to simply "concatenate" them all into one array.

For instance

$arr1 = array(1,2,3);
$arr2 = array(a,b,c);
$arr3 = array("red","white","blue");
$bigArray[] = $arr1;
$bigArray[] = $arr2;
$bigArray[] = $arr3;

Then you would have 1 Array containing three separate arrays, assuming that is what you're after.

$bigArray would look something like this

Array (
        0 Array (
           0 => 1
           1 => 2
           2 => 3
       )
        1 Array (
           0 => a
           1 => b
           2 => c
       )
        2 Array (
           0 => red
           1 => white
           2 => blue
       )
)