how to sort array in a different order - php

Question

I have an array which looks like this.
Array
(
[0] => Array
(
[cartId] => 667
[isPack] => 1
)
[1] => Array
(
[cartId] => 668
[isPack] => 1
)
[2] => Array
(
[cartId] => 672
[isPack] => 2
)
[3] => Array
(
[cartId] => 673
[isPack] => 2
)
)
I want to make an array by isPack element,which should look something like this.
Array (
[1] => Array
(
[0] => Array
(
[cartId] => 667
)
[1] => Array
(
[cartId] => 668
)
)
[2] => Array
(
[0] => Array
(
[cartId] => 672
)
[1] => Array
(
[cartId] => 673
)
)
)
Array two will be two array in which isPack will be array key,and other information will belong to its subarray.
How can I do this?
thanks in advance :)

Answer 1

$new=array();
$arr = array( array('cartId' => 667,'isPack' => 1),array('cartId' => 668,'isPack' => 1),array('cartId' => 672,'isPack' => 2),array('cartId' => 673,'isPack' => 2));
for($i=0;$i<count($arr);$i++) {
$l = $arr[$i]['isPack'];
$new[$l][]['catid']= $arr[$i]['cartId'];
}
print_r($new);
and output:-
Array
(
[1] => Array
(
[0] => Array
(
[catid] => 667
)
[1] => Array
(
[catid] => 668
)
)
[2] => Array
(
[0] => Array
(
[catid] => 672
)
[1] => Array
(
[catid] => 673
)
)
)

Answer 2

Try with:
$input = array( /* your data*/ );
$output = array();
foreach ( $input as $data ) {
$isPack = $data['isPack'];
$cartId = $data['cartId'];
if ( !isset($output[$isPack]) ) {
$output[$isPack] = array();
}
$output[$isPack][] = array(
'cartId' => $cartId
);
}