How to display the sum of global variables?

Question

PHP

How to write a function that will display the sum of global numbers.

my code is like this but not working

$a = 5;
$b = 10;

function summa(){

    $summan = $GLOBALS['a'] + $GLOBALS['b'];
    return $summan;
  }

summa();

Answer 1

Try
summa();
replacing with
var_dump(summa());