Testing for no array intersection in PHP -

i have following code:

$result = array_intersect($contacts1, $contacts2);

this generates:

array ( [21] =>  [22] =>  [23] =>  [24] =>  [25] =>  [26] =>  [28] =>

i have following if statement:

if (empty($result)) { // i.e. no interection

i realized not work test no intersection because many elements produced, value null. given best way test intersection of 2 arrays?

you can check if values null (if know no null's can exist in arrays). can use array_filter function.

for example:

$result = array_filter(array_intersect($contacts1, $contacts2));

that way, nulls removed, , result (if no intersecion exists) empty array.

update: said in comment, remove non-null values. revised version use callback function:

function filteronlynulls($elem) {     return $elem !== null; }  $result = array_filter(array_intersect($contacts1, $contacts2), "filteronlynulls");

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