PHP Functions Essential Reference

ksort

void ksort(array array, [int flag]) 

array	Array to be sorted
flag	Flag specifying how to compare key values (PHP 4.0.0+ only)

Sorts an array in ascending order by key.

Returns:

TRUE on success; NULL on failure

Description:

Performs an ascending sort based on the keys of the array rather than the values of the elements. Maintains the key/value relationships in the array.

(PHP 4.0.0+ only) The way in which element values are compared can be modified by passing one of the following named constants as flag :

SORT_REGULAR	Compare element keys according to PHP’s normal comparison rules. This is the default if flag is not given.
SORT_NUMERIC	Compare element keys according to their numeric values.
SORT_STRING	Compare element keys according ...