These functions allow you to interact with and manipulate arrays in various ways. Arrays are essential for storing, managing, and operating on sets of variables.
Simple and multi-dimensional arrays are supported, and may be either user created or created by another function. There are specific database handling functions for populating arrays from database queries, and several functions return arrays.
Please see the Arrays section of the manual for a detailed explanation of how arrays are implemented and used in PHP.
These functions are available as part of the standard module, which is always available.
There is no installation needed to use these functions, they are part of the PHP core.
This extension does not define any configuration directives.
This extension does not define any resource types.
These constants are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.
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 is used with array_change_key_case() and is used to convert array keys to upper case.