get_defined_constants
(PHP 4 >= 4.1.0, PHP 5)
get_defined_constants — Returns an associative array with the names of all the constants and their values
Description
array get_defined_constants
([ bool $categorize = false
] )
Returns the names and values of all the constants currently defined. This includes those created by extensions as well as those created with the define() function.
Parameters
- categorize
-
Causing this function to return a multi-dimensional array with categories in the keys of the first dimension and constants and their values in the second dimension.
<?php
define("MY_CONSTANT", 1);
print_r(get_defined_constants(true));
?>The above example will output something similar to:
Array ( [Core] => Array ( [E_ERROR] => 1 [E_WARNING] => 2 [E_PARSE] => 4 [E_NOTICE] => 8 [E_CORE_ERROR] => 16 [E_CORE_WARNING] => 32 [E_COMPILE_ERROR] => 64 [E_COMPILE_WARNING] => 128 [E_USER_ERROR] => 256 [E_USER_WARNING] => 512 [E_USER_NOTICE] => 1024 [E_ALL] => 2047 [TRUE] => 1 ) [pcre] => Array ( [PREG_PATTERN_ORDER] => 1 [PREG_SET_ORDER] => 2 [PREG_OFFSET_CAPTURE] => 256 [PREG_SPLIT_NO_EMPTY] => 1 [PREG_SPLIT_DELIM_CAPTURE] => 2 [PREG_SPLIT_OFFSET_CAPTURE] => 4 [PREG_GREP_INVERT] => 1 ) [user] => Array ( [MY_CONSTANT] => 1 ) )
Return Values
Changelog
Version | Description |
---|---|
5.3.1 | Windows only : Core constants are categorized under Core, previously mhash. |
5.3.0 | Core constants are categorized under Core, previously internal. On Windows, the Core Constants are categorized under mhash. |
5.2.11 | The categorize parameter now operates appropriately. Previously, the categorize parameter was interpreted as !is_null($categorize), making any value other than NULL force the constants to be categorized. |
5.0.0 | The categorize parameter was added. |
Examples
Example #1 get_defined_constants() Example
<?php
print_r(get_defined_constants());
?>
The above example will output something similar to:
Array ( [E_ERROR] => 1 [E_WARNING] => 2 [E_PARSE] => 4 [E_NOTICE] => 8 [E_CORE_ERROR] => 16 [E_CORE_WARNING] => 32 [E_COMPILE_ERROR] => 64 [E_COMPILE_WARNING] => 128 [E_USER_ERROR] => 256 [E_USER_WARNING] => 512 [E_USER_NOTICE] => 1024 [E_ALL] => 2047 [TRUE] => 1 )
See Also
- defined() - Checks whether a given named constant exists
- get_loaded_extensions() - Returns an array with the names of all modules compiled and loaded
- get_defined_functions() - Returns an array of all defined functions
- get_defined_vars() - Returns an array of all defined variables