Array sort

Before sort

Array
(
    [1] => d
    [2] => 9
    [3] => 2
    [4] => m
    [5] => Q
    [6] => e
    [7] => x
    [8] => e
    [9] => U
)

After sort

Array
(
    [0] => 2
    [1] => 9
    [2] => Q
    [3] => U
    [4] => d
    [5] => e
    [6] => e
    [7] => m
    [8] => x
)