How to group the array by the same key and value

Question

I have an array like this:D

Array
(
[0] => Array
    (
        [type] => AAA
        [label_id] => A1,35
    )

[1] => Array
    (
        [type] => AAA
        [label_id] => A2,34
    )

[2] => Array
    (
        [type] => BBB
        [label_id] => B1,29
    )

[3] => Array
    (
        [type] => CCC
        [label_id] => C1,20
    )

[4] => Array
    (
        [type] => CCC
        [label_id] => C2,19
    )

[5] => Array
    (
        [type] => CCC
        [label_id] => C3,18
    )
)

Now i would like to make it group by the same key and value like this.

Array
(
[0] => Array
    (
        [type] => AAA
        [label_id] => Array
            (
                [0] => A1,35
                [1] => A2,34
            )
    )
[1] => Array
    (
        [type] => BBB
        [label_id] => Array
            (
                [0] => B1,29
            )
    )
[2] => Array
    (
        [type] => CCC
        [label_id] => Array
            (
                [0] => C1,20
                [1] => C2,19
                [2] => C3,18
            )
   )
   )

does any one know how to do that?

Answer 1

This should do the trick

$args = array
(
    array( 'type' => 'AAA', 'label_id' => 'A1,35' ),
    array( 'type' => 'AAA', 'label_id' => 'A2,34' ),
    array( 'type' => 'BBB', 'label_id' => 'B1,29' ),
    array( 'type' => 'CCC', 'label_id' => 'C1,20' ),
    array( 'type' => 'CCC', 'label_id' => 'C2,19' ),
    array( 'type' => 'CCC', 'label_id' => 'C3,18' )  
);

$tmp = array();

foreach($args as $arg)
{
    $tmp[$arg['type']][] = $arg['label_id'];
}

$output = array();

foreach($tmp as $type => $labels)
{
    $output[] = array(
        'type' => $type,
        'label_id' => $labels
    );
}

var_dump($output);

The output is :

array
  0 => 
    array
      'type' => string 'AAA' (length=3)
      'label_id' => 
        array
          0 => string 'A1,35' (length=5)
          1 => string 'A2,34' (length=5)
  1 => 
    array
      'type' => string 'BBB' (length=3)
      'label_id' => 
        array
          0 => string 'B1,29' (length=5)
  2 => 
    array
      'type' => string 'CCC' (length=3)
      'label_id' => 
        array
          0 => string 'C1,20' (length=5)
          1 => string 'C2,19' (length=5)
          2 => string 'C3,18' (length=5)

Answer 2

<?php

$grouped_types = array();

foreach($types as $type){
        $grouped_types[$type['type']][] = $type;
}

?>