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get_defined_constants

PHP function Edit on GitHub ✎

(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)

Returns an associative array with the names of all the constants and their values

Description

get_defined_constants(bool $categorize = false): array

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.

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

<?php
define("MY_CONSTANT", 1);
print_r(get_defined_constants(true));
?>

The above example will output something similar to:

output

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
        )

)

Return Values

Returns an array of constant name => constant value array, optionally grouped by extension name registering the constant.

Examples

get_defined_constants() Example

php

<?php
print_r(get_defined_constants());
?>