将数组中的元素按两个对分配，然后找出差值和总和

Question

Let's say I have this array

$number = [2,1,4,3,6,2];

1. First pair the elements on an array by two's and find their difference so this is the output in the first requirement

   $diff[] = [1,1,4];
   

2. Second sum all the difference this is the final output

   $sum[] = [6];
   

Conditions:

1. the array size is always even
2. the first element in a pair is always greater than the second one, so their is no negative difference

What I've done so far is just counting the size of an array then after that I don't know how to pair them by two's. T_T

Is this possible in php? Is there a built in function to do it?

Answer 1

One line:

$number = [2,1,4,3,6,2];
$total = array_sum(array_map(function ($array) {
    return current($array) - next($array); 
}, array_chunk($number, 2)));
echo $total;