Add two arrays with the same length - php

Question

I have two arrays,
$arr_1 = array(01=>5, 02=>3, 03=>2);
$arr_2 = array(01=>3, 02=>4, 03=>0);
what I want to achieve is to have a single array where the final form after adding the two arrays would be,
$arr_3 = array(01=>8, 02=>7, 03=>2);
I tried array_merge but it wasn't the solution.How would I attain the final form?

Answer 1

Try array_map. From the PHP Manual
array_map() returns an array containing all the elements of arr1
after applying the callback function to each one. The number of
parameters that the callback function accepts should match the number
of arrays passed to the array_map()
$arr_1 = array(01=>5, 02=>3, 03=>2);
$arr_2 = array(01=>3, 02=>4, 03=>0);
$arr_3 = array_map('add', $arr_1, $arr_2);
function add($ar1, $ar2){
return $ar1+$ar2;
}
print_r($arr_3);
OUTPUT:
Array ( [0] => 8 [1] => 7 [2] => 2 )

Answer 2

A for loop should handle this:
$max = count($arr_1);
$arr_3 = array();
for($i = 0; $i < $max; $i++){
$arr_3[$i] = intval($arr_1[$i]) + intval($arr_2[$i]);
}
I'm sure there are many other ways to do this, but this is the first one that came to mind. You could also do a foreach loop:
$arr_3 = array();
foreach($arr_1 as $k => $v){
$arr_3[$k] = intval($v) + intval($arr_2[$k]);
}
I'm just winging it here, the foreach is a little tricky to avoid the cartesian effects. Worth a shot though.

Answer 3

If you require adding elements matching by their key not by their position, you could try this:
$array1 = array(1=>5, 2=>3, 3=>2);
$array2 = array(3=>3, 2=>4, 1=>0); //unsorted array
$keys_matched = array_intersect_key ( $array1 , $array2);
foreach ($keys_matched as $key => $value) {
$result[$key] = $array1[$key] + $array2[$key];
}
print_r($result); //Displays: Array ( [1] => 5 [2] => 7 [3] => 5

Answer 4

You would look through both arrays and add each value of each array together then add that result to another array.
foreach($array1 as $val1) {
foreach($array2 as $val2) {
array_push($newArray, intval($val1)+ intval(val2));
}
}