PHP 5.4.31 Released

get_defined_constants

(PHP 4 >= 4.1.0, PHP 5)

get_defined_constants Restituisve un array associativo con i nomi di tutte le costanti ed i loro valori

Descrizione

array get_defined_constants ( void )

Questa funzione restituisce i nomi ed i valori di tutte le costanti attualmente definite. Queste includono sia quelle create dalle estensioni sia quelle create con la funzione define().

Ad esempio la linea seguente:

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

visualizzerĂ  il seguente elenco:

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
)

Vedere anche: defined(), get_loaded_extensions(), get_defined_functions() e get_defined_vars().

add a note add a note

User Contributed Notes 4 notes

up
2
Bob
5 years ago
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
up
1
Anonymous
8 years ago
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] =>
)
up
1
me at gogogadgetscott dot info
9 years ago
<?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;
}
?>
up
-1
bimal at sanjaal dot com
1 year ago
Though the syntax editors mark the following as error, it executes successfully under PHP, as you desire.

<?php
$user_defined_constants
=get_defined_constants(true)['user'];
print_r($user_defined_constants);
?>

No errors/warnings seen.
Only the special thing here is, you are passing true to the function, and extracting the result's 'user' index directly.
To Top