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get_extension_funcs> <get_current_user
Last updated: Fri, 05 Sep 2008

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get_defined_constants

(PHP 4 >= 4.0.7, PHP 5)

get_defined_constantsすべての定数の名前とその値を連想配列として返す

説明

array get_defined_constants ([ mixed $categorize ] )

現在定義されている全ての定数の名前と値を返します。返される値には、 拡張モジュールにより作成された定数や define() 関数で作成された定数も含まれます。

パラメータ

categorize

これを渡すと、この関数は多次元の配列を返すようになります。 最初の次元のキーがカテゴリとなり、 そのカテゴリ内の定数とその値が下位レベルに格納されます。

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

上の例の出力は、たとえば 以下のようになります。

Array
(
    [internal] => 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
        )

)

注意: categorize パラメータの内容は何でもかまいません。 パラメータを渡したかどうかだけが判断の対象となります。

返り値

変更履歴

バージョン 説明
5.0.0 パラメータ categorize が追加されました。

例1 get_defined_constants() の例

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

上の例の出力は、たとえば 以下のようになります。

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
)



get_extension_funcs> <get_current_user
Last updated: Fri, 05 Sep 2008
 
add a note add a note User Contributed Notes
get_defined_constants
Bob
08-Aug-2008 06:50
Add this method to your class definition if you want an array of class constants (get_defined_constants doesn't work with class constants as Peter P said above):

<?php
public
function get_class_constants()
{
   
$reflect = new ReflectionClass(get_class($this));
    return
$reflect->getConstants());
}
?>

You could also override stdObject with it so that all your classes  have this method
eslindsey AT gma il dot co m
13-Aug-2007 10:12
If you need to use the values of your defined constants in strings or for example in HEREDOC syntax, use this function:

<?php

//PHP5+ only
$constarray = get_defined_constants(true);
foreach(
$constarray['user'] as $key => $val)
    eval(
sprintf('$_CONSTANTS[\'%s\'] = \'%s\';', addslashes($key), addslashes($val)));

//PHP4+ ...this is less efficient since it defines hundreds of constants
foreach(get_defined_constants() as $key => $val)
    eval(
sprintf('$_CONSTANTS[\'%s\'] = \'%s\';', addslashes($key), addslashes($val)));

?>

Once you run that you can use $_CONSTANTS['constantname'] to get the value of a constant. You'll need to erase the array and rerun the code if you define any new constants. But I found it handy when I wanted to use a couple of my defined constants in HEREDOC syntax. Don't forget: because this is not really a superglobal you'll need to globalize it if you want to use it from within a different scope, for example:

<?php

//hopefully you ran the snippet out here so that $_CONSTANTS is in global scope.

$mv = $_CONSTANTS['foo']; //works

function my_function()
{
    global
$_CONSTANTS;       //without this line it won't work in here!
   
$mv = $_CONSTANTS['bar']; //works thanks to previous line
}

?>
Peter P.
07-Jul-2007 02:38
Does not return class constants in PHP 5.
05-Jan-2006 08:29
If you want to filter through and return only the prefix for your constants (i.e. you have constants with a naming scheme), then you can use this quick little function. It comes in handy for debugging.

<?php
function returnConstants ($prefix) {
    foreach (
get_defined_constants() as $key=>$value)
        if (
substr($key,0,strlen($prefix))==$prefix$dump[$key] = $value;
    if(empty(
$dump)) { return "Error: No Constants found with prefix '".$prefix."'"; }
    else { return
$dump; }
}
?>

Example:

<?php
define
("SITENAME_OPTION_ONE",true);
define("SITENAME_OPTION_TWO",false);
define("SITENAME_URL","foo");

print_r(returnConstants("SITENAME_OPTION"));
?>

Will return:

Array
(
    [SITENAME_OPTIONONE] => 1
    [SITENAME_OPTIONTWO] =>
)
me at gogogadgetscott dot info
18-Jun-2005 08:14
<?php
/**
 * Convert constant value into string name.
 *
 * @param  mixed  Constant value.
 * @return string Constant name.
 * @access public
 */
function sch_get_consant($value)
{
   
$constants = get_defined_constants();
   
$name = array_search($value, $constants, TRUE);   
    return
$name;
}
?>

get_extension_funcs> <get_current_user
Last updated: Fri, 05 Sep 2008
 
 
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