PHP multiply values of a multidimensional array - php

Question

I've tried searching for this as I don't think it's that unique that no one has tried to do it. I just can't figure out the right keywords to search for to find my answer!
I have this array
array(
0 => array(
'oranges'=> 4.00,
'apples' => 2.00,
),
1 => array(
'oranges' => 2.00,
'apples' => 1.82,
'peaches' => 1.2,
),
2 => array(
'oranges' => 2.20,
),
);
What I want to do is find the value of all the oranges values multiplied together so (4 * 2 * 2.20) and all the values of apples multiplied together so (2 * 1.82).
The amount of arrays of values is variable and the amount of values inside the arrays is variable.

Answer 1

This uses a combination of foreach, isset, and your run-of-the-mill if/else statements.
$products = array();
foreach ($array as $a) {
foreach ($a as $key => $value) {
if (!isset($products[$key])) $products[$key] = $value;
else $products[$key] = $products[$key] * $value;
}
}
var_dump($products);
Should be self-explanatory since all you're doing is taking the product of all of the lowest level elements with the same keys.

Answer 2

Though sjagr’s answer is the best solution possible, I have an alternative approach with array_column (PHP 5 >= 5.5.0) which requires only one foreach loop:
<?php
$arr = array(
array(
"oranges" => 4.00,
"apples" => 2.00
),
array(
"oranges" => 2.00,
"apples" => 1.82,
"peaches" => 1.2
),
array(
"oranges" => 2.20
)
);
$_arr = array();
foreach(array("oranges", "apples", "peaches") as $val){
$_arr[$val] = array_product(array_column($arr, $val));
}
print_r($_arr);
?>
The result will be:
Array
(
[oranges] => 17.6
[apples] => 3.64
[peaches] => 1.2
)
Demo: https://eval.in/82322