How to check if an associative array has an empty or null value

Looked at all the answers and I don't like them. Isn't this much simpler and better? It's what I am using:

  if (in_array(null, $array, true) || in_array('', $array, true)) {
    // There are null (or empty) values.
  }

Note that setting the third parameter as true means strict comparison, this means 0 will not equal null - however, neither will empty strings ('') - this is why we have two conditions. Unfortunately the first parameter in in_array has to be a string and cannot be an array of values.

use array_key_exists() and is_null() for that. It will return TRUE if the key exists and has a value far from NULL

Difference:

$arr = array('a' => NULL);

var_dump(array_key_exists('a', $arr)); // -->  TRUE
var_dump(isset($arr['a'])); // -->  FALSE

So you should check:

if(array_key_exists($key, $array) && is_null($array[$key])) {
    echo "key exists with a value of NULL";
}