get_declared_classes()
(PHP 4, PHP 5, PHP 7)
返回由已定义类的名字所组成的数组
说明
get_declared_classes(void): array
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 #1get_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()
返回所有已定义函数的数组
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 )
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 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...
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
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
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.
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.
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.
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.