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

Question

I know how to insert it to the end by:

$arr[] = $item;

But how to insert it to the beginning?

Answer 1

In case of an associative array or numbered array where you do not want to change the array keys:

$firstItem = array('foo' => 'bar');

$arr = $firstItem + $arr;

array_merge does not work as it always reindexes the array.