Using array_intersect on a multi-dimensional array

Question

I have two arrays that both look like this:

Array
(
    [0] => Array
        (
            [name] => STRING
            [value] => STRING
        )

    [1] => Array
        (
            [name] => STRING
            [value] => STRING
        )

    [2] => Array
        (
            [name] => STRING
            [value] => STRING
        )
)

and I would like to be able to replicate array_intersect by comparing the ID of the sub arrays within the two master arrays. So far, I haven't been successful in my attempts. :(

Answer 1

Use array_uintersect() to use a custom comparison function, like this:

$arr1 = array(
           array('name' => 'asdfjkl;', 'value' => 'foo'),
           array('name' => 'qwerty', 'value' => 'bar'),
           array('name' => 'uiop', 'value' => 'baz'),
        );

$arr2 = array(
           array('name' => 'zxcv', 'value' => 'stuff'),
           array('name' => 'asdfjkl;', 'value' => 'foo'),
           array('name' => '12345', 'value' => 'junk'),
           array('name' => 'uiop', 'value' => 'baz'),
        );

$intersect = array_uintersect($arr1, $arr2, 'compareDeepValue');
print_r($intersect);

function compareDeepValue($val1, $val2)
{
   return strcmp($val1['value'], $val2['value']);
}

which yields, as you would hope:

Array
(
    [0] => Array
        (
            [name] => asdfjkl;
            [value] => foo
        )

    [2] => Array
        (
            [name] => uiop
            [value] => baz
        )

)