How to insert an item at the beginning of an array in PHP?

Use array_unshift($array, $item);

$arr = array('item2', 'item3', 'item4');
array_unshift($arr , 'item1');
print_r($arr);

will give you

Array
(
 [0] => item1
 [1] => item2
 [2] => item3
 [3] => item4
)