在Foreach循环中动态创建数组

Question

I am trying create an array in a foreach loop, and then sort it by a key.

The for each loop creating the array looks like this:

public function index(){

    $query=$this->My_model->get_data();
    foreach ($query as $row)
    {
           $data=array(
           Array('Points'=>$points,'Name'=>$row['Name'], 'Phone'=>$row['phone']),
            );

           function cmp ($a, $b) {
        return $a['Points'] < $b['Points'] ? 1 : -1;
        }

        usort($data, "cmp");

        print_r($data);


        }
    }

But this only returns the first the first item in the array.

However when I input some array items directly such as the below, it works fine and sorts all the array items.

public function index(){

    $query=$this->My_model->get_data();
    foreach ($query as $row)
    {
         $data = array (
    Array ( 'Points' => 500, 'Name' => 'James Lion' ) ,
    Array ( 'Points' => 1200, 'Name' => 'John Smith' ), 
    Array ( 'Points' => 700, 'Name' => 'Jason Smithsonian' ) );

           function cmp ($a, $b) {
        return $a['Points'] < $b['Points'] ? 1 : -1;
        }

        usort($data, "cmp");

        print_r($data);

        }
    }

How do I fix this so that the code in the first snippet, so that works as it does in the second snippet?

Answer 1

You have to change the code piece like this

$data[]=array('Points'=>$points,'Name'=>$row['Name'], 'Phone'=>$row['phone']));

The problem with your code is , you are not creating a multidimensional array and instead overwriting the $row values in $data which eventually has the last data since all the other data is overwritten

Also move your function cmp outside of the foreach loop

Answer 2

Have you tried using your custom sort on the outside, (after building your array on the loop). Consider this example:

public function index()
{
    $query = $this->My_model->get_data();
    foreach ($query as $row) {
        $data[] = array('Points' => $points,' Name' => $row['Name'], 'Phone' => $row['phone']),);
    }

    function cmp ($a, $b) {
        return $a['Points'] < $b['Points'] ? 1 : -1;
    }

    usort($data, "cmp");
    print_r($data);
}

Answer 3

Store your values into array format lock like this $data[]

foreach ($query as $row)
    {
           $data[]=array(
           Array('Points'=>$points,'Name'=>$row['Name'], 'Phone'=>$row['phone']),
            );
   }

Then you print the data outside of foreach loop

print_r($data);