Question

I have an array AllUsers as

Array AllUsers
(
    [0] => Array
         (
             [0] => Array
                  (
                      [0] => Tim
                      [1] => [e-mail]
                  )
             [1] => Array
                  (
                      [0] => John
                      [1] => [e-mail]
                  )
         )
    [1] => Array
         (
             [0] => Array
                  (
                      [0] => Mike
                      [1] => [e-mail]
                  )
             [1] => Array
                  (
                      [0] => Aron
                      [1] => [e-mail]
                  )
         )
)

I have another array FilteredUsers as

Array FilteredUsers
(
    [0] => Array
         (
             [0] => John
             [1] => [e-mail]
         )
    [1] => Array
         (
             [0] => Mike
             [1] => [e-mail]
         )
    [2] => Array
         (
             [0] => Mike
             [1] => [e-mail]
         )
)

Now what I want is to add every element of FilteredUsers[] in AllUsers[] such that –

1. FilteredUsers[0] should get added to Batch AllUsers[1] because Batch AllUsers[0] already has array with element name John in it
2. Similarly FilteredUsers[1] should get added to Batch AllUsers[0]
3. Any Batch (like AllUsers[0], AllUsers[1]) can’t have more than 3 elements. If all Batches are full, then a new batch shall be created but every element in FilteredUsers[] should be accommodated in some Batch.

So the updated AllUsers array should be something like this –

Array AllUsers
(
    [0] => Array
         (
             [0] => Array
                  (
                      [0] => Tim
                      [1] => [e-mail]
                  )
             [1] => Array
                  (
                      [0] => John
                      [1] => [e-mail]
                  )
             [2] => Array
                  (
                      [0] => Mike
                      [1] => [e-mail]
                  )
         )
    [1] => Array
         (
             [0] => Array
                  (
                      [0] => Mike
                      [1] => [e-mail]
                  )
             [1] => Array
                  (
                      [0] => Aron
                      [1] => [e-mail]
                  )
             [2] => Array
                  (
                      [0] => John
                      [1] => [e-mail]
                  )
         )
    [2] => Array
         (
             [0] => Array
                  (
                      [0] => Mike
                      [1] => [e-mail]
                  )
         )
)

Answer 1

Here is the working code:

I have created a code pastebin also for you at: http://codepad.org/iyZUpYxc

<?php

//PHP Multidimensional Array Manipulation

$allUsers = array();
$allUsers[] = array(array('name'=>'Tim', 'email'=>'[e-mail]'), array('name'=>'John','email'=>'[e-mail]'));
$allUsers[] = array(array('name'=>'Mike', 'email'=>'[e-mail]'), array('name'=>'Aron','email'=>'[e-mail]'));

$filteredUsers = array();
$filteredUsers[] = array('name'=>'John', 'email'=>'[e-mail]');
$filteredUsers[] = array('name'=>'Mike', 'email'=>'[e-mail]');
$filteredUsers[] = array('name'=>'Mike', 'email'=>'[e-mail]');

//RULE: one batch cannot have duplicate user names

//print_r($allUsers);
//print_r($filteredUsers);

foreach ($filteredUsers as $filteredUser) {
  //$filteredUser is a single dimensional arrray.

  $filteredUserAdded = 0;
  foreach ($allUsers as &$allUser) {
     //$allUser is a muldimentional array.

     //Check whether the current batch contains $filteredUser['name'] value
     $intersect = array_uintersect(array($filteredUser), $allUser, 'compareName');
     if (empty($intersect) && count($allUser) < 3) {
         //We can add filtereduser here
         $allUser[] = $filteredUser; 
         $filteredUserAdded = 1;
     }

  } // end foreach $allUsers

  if ($filteredUserAdded == 0) {
      //This filtered user was not added in any existing batch.
      //Hence add it in a new batch
      $allUsers[] = array($filteredUser);       
  }
} // end foreach $filteredUsers


//function to compare the 'name' column value of two arrays
function compareName($array1, $array2)
{
   return strcmp($array1['name'], $array2['name']);
}

//Note: http://in1.php.net/array_uintersect is the key used here for comparison

print_r($allUsers);
print_r($filteredUsers);

?>

Note: You have missed the array
(
[0] => John
[1] => [e-mail]
) in your Output above.

But my code outputs that also correctly.

Thanks