PHP - Find the difference / subtraction between the values of two arrays

Question

I am getting values of two company stocks through a third party website using an API. These are output as two arrays eg

$companyA = array([0] => 100 [1] => 100.20  [2] => 103.20);
$companyB = array([0] => 99 [1] => 101.30  [2] => 105.50);

Each key [0],[1],[2], etc.. represents a day and is the same day for both stock dates. I would like to try and find the difference in values in the array by doing a subtraction for each value. ie 100 - 99, 100.20-101.30, 103.20 - 105.50, etc...

I tried array_diff but it's not working.

Thank you.

Answer 1

You can use array_map

$result = array_map(function ($firstElement, $secondElement) {
    return $firstElement - $secondElement;
}, $companyA, $companyB);

Answer 2

You can also try this with basics:

<?
$companyA = array(100,100.20,103.20);
$companyB = array(99,101.30,105.50);

$newArr = array();
foreach ($companyA as $key => $value) {
    $newArr[] = ($value-$companyB[$key]);
}
echo "<pre>";
print_r($newArr);
?>

Result:

Array
(
    [0] => 1
    [1] => -1.1
    [2] => -2.3
)