if statement selects switch statement

Question

I hope this makes sense. Right now I am using the following code to add up number of checkboxes check and get a shipping price based off that number. This only gets me one set off shipping prices (ground). I know want to add mulitpble shipping options so I need to add another set of switch/case statement.

//Add up club totals for shipping
            $clubTotal = array(
                            $driversChecked,
                            $hybridsChecked,
                            $woodsChecked,
                            $boxesChecked,
                            $wedgesChecked,
                            );  

            //see what shipping was picked
            $shippingChoice = $_POST['ShipMethod'];

            //Figure out ground shipping
            if (array_sum($clubTotal))
            {
                switch(array_sum($clubTotal))
                {
                    case 6:
                        $shippingCost =  15.99 ;
                        break ;

                    case 7:
                    case 8:
                        $shippingCost =  16.99 ;
                        break ;

                    case 9:
                    case 10:
                        $shippingCost =  17.99 ;
                        break ;

                    case 11:
                    case 12:
                        $shippingCost =  18.99 ;
                        break ;

                    case 13:
                        $shippingCost =  19.99 ;
                    break ;

                    case 14:
                        $shippingCost =  20.99 ;
                    break ;

                    case 15:
                        $shippingCost =  21.99 ;
                    break ;

                    case 16:
                        $shippingCost = 22.99;
                    break ;

                    default:
                        $shippingCost = 14.99;
                        break ;
                }
            }

If $shippingChoice = $_POST['ShipMethod']; is getting my ship method, how can I use that to select what switch/case statement to use. Like if $shippingChoice returned the value of "ground" it would use my current switch/case statement.If it returned "2 Day" it would use another switch/case statement I would make.

Answer 1

You want something like this? Add a subarray for other shipping methods.

$shippingCostData = array(
    'ground' => array(
        6 => 15.99,
        7 => 16.99,
        8 => 16.99,
        9 => 17.99,
        10 => 17.99,
        11 => 18.99,
        12 => 18.99,
        13 => 19.99,
        14 => 20.99,
        15 => 21.99,
        16 => 22.99,
        'default' => 14.99,
    ),
);

$method = 'ground';
$clubTotalSum = array_sum($clubTotal);
$shippingCost = (isset($shippingCostData[$method][$clubTotalSum]) ? $shippingCostData[$method][$clubTotalSum] : $shippingCostData[$method]['default']);

You can also use something like this to filter shipping methods to make sure it is valid.

$method = (isset($shippingCostData[$_POST['shippingMethod']]) ? $_POST['shippingMethod'] : key($shippingCostData));

Answer 2

You should define the shipping charges in another form that is more malleable at run time. For example:

$costs = [
    1 => 14.99, // 1 or more = 14.99
    6 => 15.99, // 6 or more
    7 => 16.99,
    9 => 17.99,
];

You can then write a function that takes the number and the costs array and returns the cost:

function calculateCost($items, $costs) {
    ksort($costs); // just to be on the safe side
    $result = reset($costs);
    foreach($costs as $number => $cost) {
        if ($number > $items) break;
        $result = $cost;
    }

    return $result;
}

After you have done this, it's easy to keep multiple costs arrays and forward to the one you need, e.g.

$costs = [
    'ground' => [
        1 => 14.99,
        6 => 15.99,
    ],
    'air' => [
        1 => 24.99,
        6 => 25.99,
    ],
];

$shippingChoice = $_POST['ShipMethod'];
$cost = calculateCost(array_sum($clubTotal), $costs[$shippingChoice]);

You can easily extend this to as many shipping methods as you like.