Create multiple arrays with different values from an array

Question

I need to create 3 array with 3 different random values from a simple php array. What is the best approach for that? Choosing random keys with array_rand() then filter the keys from the array and choose another set of random keys again?

$input = array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16);

Example output:

array1 : 4, 2, 7
array2 : 8, 3, 15
array3 : 16, 1, 11

Answer 1

Shuffle it, truncate it to 9 elements, chunk it in 3's.

Code: (Demo)

$input = array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16);
shuffle($input);
var_export(array_chunk(array_slice($input,0,9),3));

Possible Output:

array (
  0 => 
  array (
    0 => 5,
    1 => 2,
    2 => 11,
  ),
  1 => 
  array (
    0 => 3,
    1 => 8,
    2 => 4,
  ),
  2 => 
  array (
    0 => 12,
    1 => 13,
    2 => 15,
  ),
)