How to add second value of 2 dimensional array together?

Question

I have a two dimensional array.

arr["id1"][10]
arr["id2"][20]

How to i add the second value of each item together.

eg 10 + 20 = 30 (return)

I need to run through all items in the array and add the second value together.

Answer 1

$res = 0;

foreach($arr as $v) {
  $res += $v;
}

like this you add the value of each item to $res

Answer 2

This is sooo weird, but I'm in the mood for some puzzle solving.

<?php

$odd_data["id1"][10] = 'Food item one';
$odd_data["id2"][20] = 'Food item two';

echo add_the_second_array_keys_of_the_array($odd_data);

function add_the_second_array_keys_of_the_array($odd_data)
{
   $total = 0;
    foreach($odd_data as $id)
    {
        foreach($id as $number=>$the_message)
        {
            $total += $number;   
        }
    }
    return $total;
}

Answer 3

function collapse($array){
  return array_keys($array)[0];
}
print array_sum(array_map('collapse', $arr));

Answer 4

$result = array();

function sort($arr) {
    for($i=0; $i < sizeof($arr); $i+2)
    {
        $result[$i] = $arr[$i] + $arr[$i+1];
    }
}

this will have result storing the summing values. (the keys's although will jump by 2 eg 1, 3, 5 ...)