sum and minus array function php

What is the easiest way to achieve:

a => 1, b =>  0, c=> 3
a => 0, b => 10, c=> 1

Sum

a => 1, b =>10, c=>4

and

Minus

a => -1, b=> 10, c=> -2

I hope my examples make it clear... If you have any questions please leave a com开发者_开发百科ment

Sum:

$array1 = array('a' => 1, 'b' => 0, 'c' => 3);
$array2 = array('a' => 0, 'b' => 10, 'c' => 1);

$result = array();
foreach ($array1 as $key => $value)
  $result[$key] = $value + $array2[$key];

You can implement the difference part similarly.

 $sum = $minus = 0;
 foreach ($arrays as $key=>$val)
 {
   $sum   += $val;
   $minus -= ($val*-1);
 }

You want to add orsubstarct the values with same key.

Try to write function with array_walk

http://php.net/manual/en/function.array-walk.php

or put in a loop and add or substarct based on key.