How to pass an array into a function, and return the results with an array

Question

So I\'m trying to learn how to pass arrays through a function, so that I can get around PHP\'s inability to return multiple values. Haven\'t been able to get anything to work so

Answer 1

You're passing the array into the function by copy. Only objects are passed by reference in PHP, and an array is not an object. Here's what you do (note the &)

function foo(&$arr) { # note the &
  $arr[3] = $arr[0]+$arr[1]+$arr[2];
}
$waffles = array(1,2,3);
foo($waffles);
echo $waffles[3]; # prints 6

That aside, I'm not sure why you would do that particular operation like that. Why not just return the sum instead of assigning it to a new array element?