Array sort

Before sort

Array
(
    [1] => P
    [2] => o
    [3] => o
    [4] => S
    [5] => 5
    [6] => r
    [7] => g
    [8] => I
    [9] => d
)

After sort

Array
(
    [0] => 5
    [1] => I
    [2] => P
    [3] => S
    [4] => d
    [5] => g
    [6] => o
    [7] => o
    [8] => r
)