Question

Possible Duplicate:
Merge 2 Arrays and Sum the Values (Numeric Keys)

I have two arrays both have same keys, i want to add key values,

Example

$arr1 = array("first"=>10,"second"=>20);
$arr2 = array("first"=>20,"second"=>30);

want to create new array which add these two array values 

like

$arr3 = array("first"=>30,"second"=>50);

How can i do that in one line, i can do it using forach or other technique, but wondering if some one know a good way of doing?

Answer 1

Example for string keys (note that no error checking is done!):

$arr1 = array("first"=>10,"second"=>20);
$arr2 = array("first"=>20,"second"=>30);

$arr3 = $arr1;
array_walk($arr3, function (&$val, $key, $foo) { $val += $foo[$key]; }, $arr2);

print_r($arr3);

/*Array
(
    [first] => 30
    [second] => 50
)*/