Online PHP editor | refs for BlWK0

<?php // Surprise surprise! When the 2nd array param of array_diff() contains an elemant with value false, // the result will no longer contain null values. class foo { } function myIsset($value) { return isset($value); } $array1 = array( 'null1' => null, 'null2' => null, 'bool' => true, ); $filtered_array1 = array_filter($array1, 'myIsset'); var_dump($array1, $filtered_array1, array_diff($array1, $filtered_array1)); $array2 = $array1; $array2['bool'] = false; $filtered_array2 = array_filter($array2, 'myIsset'); var_dump($array2, $filtered_array2, array_diff($array2, $filtered_array2));