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

说明

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.

参数

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)); ?>

以上例程的输出类似于：

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
        )

)

返回值

更新日志

版本	说明
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.

范例

Example #1 get_defined_constants() Example


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

以上例程的输出类似于：

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
)

参见

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() - 返回由所有已定义变量所组成的数组