Question

Like:

$arr1['X'] = 5;
$arr2['Y'] = &$arr1['X'];
$arr1['X'] = 7;

print $arr2['Y']; // prints 7

I tried this and I don’t see any memory usage decrease (my array has ~1000 entries), so I guess PHP makes a clone of the array or something? So technically its not really a reference, is it?

My array has sub-arrays (key=>value pairs) instead of numbers. I noticed that if I make them objects, memory usage is lower (~2MB less)

Answer 1

If you issue:

$arr2 = &$arr1;

You reference the whole array, and it should consume less memory. You can measure it with XDEBUG for instance, which I assume is what you are using.