&reftitle.constants; &extension.constants.core; CASE_LOWER (integer) CASE_LOWER is used with array_change_key_case and is used to convert array keys to lower case. This is also the default case for array_change_key_case. CASE_UPPER (integer) CASE_UPPER is used with array_change_key_case and is used to convert array keys to upper case. Sorting order flags: SORT_ASC (integer) SORT_ASC is used with array_multisort to sort in ascending order. SORT_DESC (integer) SORT_DESC is used with array_multisort to sort in descending order. Sorting type flags: used by various sort functions SORT_REGULAR (integer) SORT_REGULAR is used to compare items normally. SORT_NUMERIC (integer) SORT_NUMERIC is used to compare items numerically. SORT_STRING (integer) SORT_STRING is used to compare items as strings.