get_declared_classes

(PHP 4, PHP 5, PHP 7)

get_declared_classes — 返回由已定义类的名字所组成的数组

说明

array get_declared_classes ( void )

返回由当前脚本中已定义类的名字组成的数组。

返回值

返回由当前脚本中已定义类的名字组成的数组。

Note:

需要注意的是额外类的出现依赖于你已编译到 PHP 中的库。这意味着你不能使用这些类名定义自己的类。在附录的预定义类部分有预定义类的列表。

范例

Example #1 get_declared_classes() 例子

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

以上例程的输出类似于：

Array
(
    [0] => stdClass
    [1] => __PHP_Incomplete_Class
    [2] => Directory
)

参见

class_exists() - 检查类是否已定义
get_declared_interfaces() - 返回一个数组包含所有已声明的接口
get_defined_functions() - Returns an array of all defined functions

用户评论:

[#1] brain at code dot com [2014-02-14 08:53:43]

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...

[#2] yarco dot wang at gmail dot com [2013-11-24 19:32:22]

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.

[#3] dcahh at gmx de [2008-02-29 09:23:12]

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.

[#4] dexen + goofy _ pl [2007-09-25 11:32:52]

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

[#5] matt at mattsoft dot net [2005-12-21 02:58:11]

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

[#6] [2005-03-22 09:16:54]

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.

[#7] matt-php at DONT-SPAM-ME dot bitdifferent dot com [2004-11-01 07:41:05]

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
)

[#8] Jazeps Basko [2004-02-07 11:52:20]

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.

[#9] smokey [2003-03-20 15:06:15]

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.