如何在php中交换数组元素？

Question

I have an array

           Array
                (
                    [0] => Array
                        (                                
                            [order_id] => 1318
                            [code] => shipping
                            [title] => UK Shipping  (Weight: 0.00kg)
                            [value] => 10.2000                                
                        )

                    [1] => Array
                        (

                            [order_id] => 1318
                            [code] => sub_total
                            [title] => Sub-Total
                            [value] => 4.7000                                
                        )

                    [2] => Array
                        (                                
                            [order_id] => 1318
                            [code] => coupon
                            [title] => Coupon (10P)
                            [value] => -0.4700                                
                        )

                    [3] => Array
                        (                                
                            [order_id] => 1318
                            [code] => tax
                            [title] => VAT (20%)
                            [value] => 2.8860
                            [sort_order] => 8
                        )

                    [4] => Array
                        (                                
                            [order_id] => 1318
                            [code] => total
                            [title] => Total
                            [value] => 17.3160                                
                        )
                    )

I want to swap the array index. I want to swap the array index when [code] => coupon to [code] => sub_total, If coupon is available. I want the position of coupon to above the subtotal. I want the position of sub_total to above the vat. How is it possible? Please help me.

Answer 1

You can define a custom sort order array that puts each of the possible values of code in the order you want.

$custom_sort_order = array(
    'shipping' => 1,
    'coupon' => 2,
    'sub_total' => 3,
    'tax' => 4,
    'total' => 5);

then you can use that custom sort order in the comparison function of usort to get the array items in your desired order.

usort($your_array, function($x, $y) use ($custom_sort_order) {

    // find the sort number for each item
    $x = $custom_sort_order[$x['code']];
    $y = $custom_sort_order[$y['code']];

    // do the comparison
    if ($x == $y) return 0;
    return $x - $y;
});