array key value not sending in php code example

Example 1: php all keys in array

<?php
$array = array(
    'fruit1' => 'apple',
    'fruit2' => 'orange',
    'fruit3' => 'grape',
    'fruit4' => 'apple',
    'fruit5' => 'apple');

$keys = array_keys($array);		// return array
$values = array_values($array);	// return array
?>

Example 2: php array all keys empty

array('key1' => null, 'key2' => null, 'key3' => null, 'key4' => null)
if (!array_filter($array)) {
    // all values are empty (where "empty" means == false)
}