What's the best way to do this? - php

Question

I am trying to get different sums depending on certain conditions, there needs to be 20 different variables which will be returned at the end of the function. I feel like there should be an easier way to do it? Thanks for any help in advanced.
function getTotalNutrients($id)
{
$applications = $this->getApplications($id);
$nsum = 0;
$psum = 0;
$ksum = 0;
$mgsum = 0;
// ...
foreach( $applications as $pro ) {
$details = $this->getAppliedNutrients($pro->id);
foreach($details as $nutrients){
switch($pro->area){
case "1":
$nsum += ($nutrients->n);
$psum += $nutrients->p;
$ksum += $nutrients->k;
$mgsum += $nutrients->mg;
break;
case "2":
$tnsum += ($nutreients->n);
// ...
break;
case "3":
$fnsum += ($nutreients->n);
//...
break;
case "4":
// ...
break;
case "5":
// ...
break;
}
}
}
return array(
$nsum,
$psum,
$ksum,
$mgsum,
$tnsum,
// etc..
);
}

Answer 1

create an array by adding all values like
$arraySum[] = array();
$arraySum[] = $nsum;
$arraySum[] = $tnsum;
.
.
.
ect
at the end
use
array_sum($arraySum);
If it is not fullfill your requirement. provide your code completely.

Answer 2

You have a case of design patterns here my friend...
Instead of using a large switch (breaks the Open/Closed principle) you should create an interface that calculates the different sums and returns a tupple (set of different values) of your choice.
Then create those AREAS of yours following the interface details. Once all your areas calculators are created, just create each of them and put them in an array based on the id. Then, load the right one using the id and calculate your values returned in a tupple...
Your code will look much tidier!