Question

So I know there’s an easy way to see the difference between two arrays using array_diff.
Take a look at why I need something a bit more specific though:

Let’s say we have these 2 arrays

$array1         $array2
   1               1
   2               -
   -               3
   4               4
   -               5
   6               -

The - indicates it is missing from the opposing array.

If $array1 contains a missing element from $array2, it must be dropped from $array1.
If $array2 contains a missing element from $array1, it must be added to $array1.

If I simply perform array_diff($array1, $array2), it will only return me [2, 6]. This isn’t helpful in my scenario because I don’t know which of the two arrays these items are missing from.

I did a bit of looking around and didn’t seem to find out if there is a native php function that will distinguish the arrays the items are missing from.

What would be the best way to go about this? I was thinking of looping $array1 and checking it against $array2 and storing the results missing in a third array, and visa-versa for a fourth array.

Is that the best way? or is there an even easier, native function i can use?

Answer 1

$comparison1 = array_diff($array1, $array2);
$comparison2 = array_diff($array2, $array1);