Help regrouping an array

I'd like to regroup my array. I have the following:

Array
(
    [0] => Array
        (
            [name] => test1
            [item_id] => 1
            [category] => cat1
        )
    [1] => Array
        (
            [name] => test2
            [item_id] => 2
            [category] => cat1
        )
    [2] => Array
        (
            [name] => test3
            [item_id] => 3
            [category] =开发者_如何学Go> cat1
        )
    [3] => Array
        (
            [name] => test4
            [item_id] => 4
            [category] => cat2
        )
)

I'd like to regroup it like this:

Array
(
    [cat1] => Array
        (
            [0] => Array
            (
                [name] => test1
                [item_id] => 1
            )
            [1] => Array
            (
                [name] => test2
                [item_id] => 2
            )
            [2] => Array
            (
                [name] => test3
                [item_id] => 3
            )
        )
    [cat2] => Array
        (
            [name] => test4
            [item_id] => 4
        )
)

Can someone tell me how this is best done?

Just loop through it and regroup it... for example:

$array = array(
    array(
        'name'      =>  'test1',
        'itemd_id'  =>  1,
        'category'  =>  'cat1',
    ),
    array(
        'name'      =>  'test2',
        'itemd_id'  =>  2,
        'category'  =>  'cat1',
    ),
    array(
        'name'      =>  'test3',
        'itemd_id'  =>  3,
        'category'  =>  'cat1',
    ),
    array(
        'name'      =>  'test4',
        'itemd_id'  =>  4,
        'category'  =>  'cat2',
    ),
);

$newArray = array();

foreach($array as $arrayKey => $arrayElement){
    $tmpCat = $arrayElement['category'];
    unset($arrayElement['category']);
    $newArray[$tmpCat][] =  $arrayElement;

}


var_dump($newArray);

array(2) {
  ["cat1"]=>
  array(3) {
    [0]=>
    array(2) {
      ["name"]=>
      string(5) "test1"
      ["itemd_id"]=>
      int(1)
    }
    [1]=>
    array(2) {
      ["name"]=>
      string(5) "test2"
      ["itemd_id"]=>
      int(2)
    }
    [2]=>
    array(2) {
      ["name"]=>
      string(5) "test3"
      ["itemd_id"]=>
      int(3)
    }
  }
  ["cat2"]=>
  array(1) {
    [0]=>
    array(2) {
      ["name"]=>
      string(5) "test4"
      ["itemd_id"]=>
      int(4)
    }
  }
}