Moving up/down an item in the array by its value

Question

I cannot find an effective solution on rearranging/swapping an array item by its value by shifting by - 1 or + 1. I\'m making an order on tables, i

Answer 1

Shifting up (assuming you've checked that the item is not already the first one):

$item = $array[ $index ];
$array[ $index ] = $array[ $index - 1 ];
$array[ $index - 1 ] = $item;

Shifting down:

$item = $array[ $index ];
$array[ $index ] = $array[ $index + 1 ];
$array[ $index + 1 ] = $item;