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(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)
get_defined_constants — Returns an associative array with the names of all the constants and their values
Returns the names and values of all currently defined constants. This includes constants defined by extensions and those created using the define() function. However, it excludes magic constants, which resolve at compile time.
categorizeCausing 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] => 30719
[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
)
)
Returns an array of constant name => constant value array, optionally grouped by extension name registering the constant.
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] => 30719
[TRUE] => 1
)
