MetaClass supports runtime access to metadata associated with Java program elements or artefacts. The program elements include packages, classes, methods, and fields and each metadata element is referred to as an attribute. The attributes are usually specified in the Java source files as JavaDoc markup.
a class defined strictly for the purpose of naming a set of attributes
a class object whose instances are themselves classes
a Class whose Extension is a set of Classes
an abstraction of its instances
a template for creating objects
a class describing other classes
Enables the creation of class objects. All class objects are instances of the metaclass object. In Object COBOL, the metaclass is Behavior, which is part of the Class Library.
The specification of a class; the complete description of a class's attributes, behavior and implementation. Every class has a metaclass, of which it is the sole instance. Contrast with class.
1. a class whose instances are classes. 2. (of an object) the class of the class of the object.
The class of a class. Class definitions create a class name, a class dictionary, and a list of base classes. The metaclass is responsible for taking those three arguments and creating the class. Most object oriented programming languages provide a default implementation. What makes Python special is that it is possible to create custom metaclasses. Most users never need this tool, but when the need arises, metaclasses can provide powerful, elegant solutions. They have been used for logging attribute access, adding thread-safety, tracking object creation, implementing singletons, and many other tasks.
A metaclass is class whose instances are classes. Metaclasses are typically used to construct metamodels. A metaclass can be modeled as a stereotype of a class using the keyword metaclass.
(1.) In AIXwindows and Enhanced X-Windows, an object class that does not instantiate widgets or gadgets but is capable of passing a unique set of inheritable resources to the subclasses beneath it in the class hierarchy. Each instance of a widget subclass has the features common to that widget class and exports these features to child widgets of that class. Included in this class are Core, Composite, Constraint, Primitive, Button, Manager, MenuMgr, and MenuPane. (2.) In SOM, a class whose instances are classes. In SOM, any class descended from SOMClass is a metaclass. The methods a class inherits from its metaclass are sometimes called class methods (in Smalltalk) or factory methods (in Objective-C) or constructors. See also class method.
In object-oriented programming, a metaclass is a class whose instances are classes. Just as an ordinary class defines the behavior of certain objects, a metaclass defines the behavior of certain classes and their instances.
