Regarding note of 3-21:
<?php
class myclass {}
$class = 'myclass';
$instance = new $class();
?>
This function could also be used to determine the names of classes defined in a particular file by calling it before and after include. It's hardly a pointless function.
get_declared_classes
(PHP 4, PHP 5, PHP 7, PHP 8)
get_declared_classes — Restituisce un array con i nomi delle classi definite
Valori restituiti
Restituisce un array con i nomi delle classi dichiarate nel codice corrente.
Nota:
Notare che in base alle estensioni compilate o caricate in PHP, potrebbero essere presenti classi aggiuntive. Questo significa che non si sarà in grado di definire le proprie classi usando questi nomi. C'è una lista delle classi predefinite nella sezione Classi Predefinite dell'appendice.
Esempi
Example #1 Esempio di get_declared_classes()
<?php
print_r(get_declared_classes());
?>Il precedente esempio visualizzerà qualcosa simile a:
Array
(
[0] => stdClass
[1] => __PHP_Incomplete_Class
[2] => Directory
)
Vedere anche:
- class_exists() - Verifica se la classe è stata definita
- get_declared_interfaces() - Returns an array of all declared interfaces
- get_defined_functions() - Returns an array of all defined functions
add a note
User Contributed Notes 10 notes
Anonymous ¶
19 years ago
matt-php at DONT-SPAM-ME dot bitdifferent dot com ¶
20 years ago
The array returned by this function will be in the order the classes were defined / included / required and this order does not appear to change.
For example:
<?PHP
//define classone
class classone { }
//define classtwo
class classtwo { }
//This will show X classes (built-ins, extensions etc) with
//classone and classtwo as the last two elements
print_r(get_declared_classes());
//define classthree
class classthree { }
//...and four
class classfour { }
//Shows the same result as before with class three and four appended
print_r(get_declared_classes());
?>
Output:
Array
(
[0] => stdClass
[1] .... other defined classes....
[10] => classone
[11] => classtwo
)
and...
Array
(
[0] => stdClass
[1] .... other defined classes....
[10] => classone
[11] => classtwo
[12] => classthree
[13] => classfour
)
rmamdaminov at gmail dot com ¶
1 year ago
Note that this function also counts enums.
<?php
enum Bla
{
case Foo;
}
var_dump(get_declared_classes());
?>
Result:
array(116) {
...
[115]=> string(3) "Bla"
}
dexen + goofy _ pl ¶
17 years ago
Summary:
* in PHP 5.1 class names have case preserved
* contrary, in PHP 4.4 class names are downcased, withe exception of a few build-in ones
The get_declared_classes() funcition returns the list of names with case preserved, as of PHP 5.1 series (prolly 5.0 too, but i have no way to test it right now). Since PHP generally is caseless in regard to names of classes, this may come at a surprise. Also, this could potentially break older code asssuming downcased list.
Take extra care when checking for existence of a class. Following example is, potentially, error prone: <?php in_array( $className, $classget_declared_classes() ) ?>
A sure-fire (while slower) way would be to iterate over the array and normalize case to, say, lower:
<?php
$exists = FALSE;
$className = strtolower( $className );
foreach ( get_declared_classes() as $c ) {
if ( $className === strtolower( $c ) ) {
$exists = TRUE;
break;
}
}?>
Optimization of the above snippet is left as a simple excercise to the reader ;)
-- dexen deVries
brain at code dot com ¶
10 years ago
get-declared-classes makes no sense at all, if u maybe, later for production, merge class files in one package file.
lets say: package.php
print_r(get_declared_classes());
class declaredHere { }
print_r(get_declared_classes());
so in this case, the declaredHerr class is defined at the first call of print_r();
because PHP-complier runs a hole file and declare Stuff before running the code.
But (Lovely PHP):
print_r(get_declared_classes());
if(true){
class declaredHere { }
}
print_r(get_declared_classes());
Will print the declaredHere class only in the second print_r.
Its not a Bug it a...
smokey ¶
21 years ago
you cannot remove them. they are "defined", which happens when the class is being loaded from the parser. you just deleted an instance of a class.
matt at mattsoft dot net ¶
18 years ago
classes can't be unloaded. probably not very practical to implement that in a future version. I wouldn't go out of my way to do it if I were zend. you're better off finding a workaround. it's better programming technique to find a way around having to do that anyway.
http://www.zend.com/zend/week/week223.php#Heading10
dcahh at gmx de ¶
16 years ago
This function considers only classes and subclasses. Not subsubclasses.
In fact I have code that provides an abstract class and then classes using this abstract class. Further I have subclasses to my concrete classes - which is why my subclasses are not listed within the returned array.
Jazeps Basko ¶
20 years ago
In PHP5, you don't get declared interfaces by calling this function!!!
To get interfaces you should use get_declared_interfaces(). However, to check if an interface is already defined, you should use class_exists()! This is strange, but PHP team does not think so.
yarco dot wang at gmail dot com ¶
10 years ago
those above comments are too old.
now, whatever the order is, the output will be the same:
<?php
class Test1
{}
print_r(get_declared_classes());
class Test2
{}
print_r(get_declared_classes());
?>
will output the same result.
