©
本文檔使用 php中文網手册 發布
(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
返回由当前脚本中已定义类的名字组成的数组。
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。
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 )
[#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.