PHP : how to multiply two arrays element-wise

Question

I want to multiply two PHP arrays element-wise.

E.g.

a = [1,2,3]

b = [2,3,4]

output = [2,6,12]

Is there any PHP function to do this?

Answer 1

I do not think there is a PHP function to multiply two arrays element-wise. However, you can use the array_map() function to call a user-defined function where you can do element-wise multiplication.

Here is an example to show how to use the array_map() function for element-wise multiplication:

<?php

function compute_mult($v1, $v2){
  return $v1*$v2;
}

$arr1 = array(1,2,3,4,5);
$arr2 = array(2,3,4,5,6);

print_r(array_map("compute_mult", $arr1, $arr2));
?>

The output of the above code is:

Array
(
    [0] => 2
    [1] => 6
    [2] => 12
    [3] => 20
    [4] => 30
)