PHP check any key of array has null value

Question

I have a array like

$question = array(
'description'=>'some description',
'answer_one'=>'some answer',
'answer_two' => NULL)

I need to check any key of this array contains null value in quickest way.

Answer 1

$key = array_search(null, $question);

Answer 2

Try this:

$question = array(
'description'=>'some description',
'answer_one'=>'some answer',
'answer_two' => NULL);

foreach ($question as $key => $value) {
    if ($value == "") {
echo $key . " is empty!";
}

}

Answer 3

if (in_array(NULL, $question)) {

}