类/对象 函数
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get_declared_classes

(PHP 4, PHP 5)

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


类/对象 函数
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用户评论:

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.

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

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

(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.

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
)

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.

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.

Leigh Purdie (2003-01-23 01:01:37)

Note that classes remain in the declared list, even when their associated object is undef'd.
eg:
$object = new MyClass;
print_r(get_declared_classes());
undef($object);
print_r(get_declared_classes());
- the two print_r's will return the same data.
Not sure how to remove a class from the declared list.

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