从现有数组创建另一个多维数组并对多维数组进行排序[关闭]

Question

i have question about php arrays. i have array like $data.

$data=array(array('a'=>'1','b'=>'2','c'=>'3','d'=>'4'),array('a'=>'5','b'=>'6','c'=>'7','d'=>'8'),array('a'=>'9','b'=>'10','c'=>'11','d'=>'12'));

i want to get only a,c,d element and create another multi dimensional array like $data1.

$data1=array(
        array('a'=>'1','c'=>'3','d'=>'4'),
            array('a'=>'5','c'=>'7','d'=>'8'),
            array('a'=>'9','c'=>'11','d'=>'12')         
        );

as a next step i wanted to sort $data1 array by first value of d elements then by value of c elements and finally by a elements and get array like $data2.

$data2=array(           
            array('a'=>'9','c'=>'11','d'=>'12')
            array('a'=>'5','c'=>'7','d'=>'8'),
            array('a'=>'1','c'=>'3','d'=>'4')
            );

i need little bit explained answer to each step. i'm stuck in here this problem. i want help.. and are there any php array function available for get $data1 array from $data easily?

Answer 1

This will work in your case..

$data=array(array('a'=>'1','b'=>'2','c'=>'3','d'=>'4'),array('a'=>'5','b'=>'6','c'=>'7','d'=>'8'),array('a'=>'9','b'=>'10','c'=>'11','d'=>'12'));
$data1 = array();

//getting data1 by removing the b's 

foreach($data as $d){
   while(list($k,$v) = each($d)){
    if($k == "b"){
        unset($d[$k]);
    }
}
array_push($data1, $d);
}

//Sorting the arrays
foreach($data1 as $key => $value){
  $ds[$key] = $value["d"];
  $cs[$key] = $value["c"];
  $as[$key] = $value["a"];
}

array_multisort($ds, SORT_DESC, $cs, SORT_DESC, $as, SORT_DESC, $data1);
print_r($data1);

This will print:

Array
(
[0] => Array
    (
        [a] => 9
        [c] => 11
        [d] => 12
    )

[1] => Array
    (
        [a] => 5
        [c] => 7
        [d] => 8
    )

[2] => Array
    (
        [a] => 1
        [c] => 3
        [d] => 4
    )

)

Dins