Predefined Constants

The constants below are always available as part of the PHP 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.

SORT_LOCALE_STRING ( integer )

SORT_LOCALE_STRING is used to compare items as strings, based on the current locale. Added in PHP 4.4.0 and 5.0.2.

COUNT_NORMAL ( integer )

COUNT_RECURSIVE ( integer )

EXTR_OVERWRITE ( integer )

EXTR_SKIP ( integer )

EXTR_PREFIX_SAME ( integer )

EXTR_PREFIX_ALL ( integer )

EXTR_PREFIX_INVALID ( integer )

EXTR_PREFIX_IF_EXISTS ( integer )

EXTR_IF_EXISTS ( integer )

EXTR_REFS ( integer )