Search results
Results From The WOW.Com Content Network
An abstract class may provide implementations of some methods, and may also specify virtual methods via signatures that are to be implemented by direct or indirect descendants of the abstract class. Before a class derived from an abstract class can be instantiated, all abstract methods of its parent classes must be implemented by some class in ...
In computer programming, a collection is an abstract data type that is a grouping of items that can be used in a polymorphic way. Often, the items are of the same data type such as int or string . Sometimes the items derive from a common type; even deriving from the most general type of a programming language such as object or variant .
By default, all methods in all classes are concrete, unless the abstract keyword is used. An abstract class may include abstract methods, which have no implementation. By default, all methods in all interfaces are abstract, unless the default keyword is used. The default keyword can be used to specify a concrete method in an interface.
Modern object-oriented languages, such as C++ and Java, support a form of abstract data types. When a class is used as a type, it is an abstract type that refers to a hidden representation. In this model, an ADT is typically implemented as a class, and each instance of the ADT is usually an object of that class.
A singleton implementation may use lazy initialization in which the instance is created when the static method is first invoked. In multithreaded programs, this can cause race conditions that result in the creation of multiple instances. The following Java 5+ example [6] is a thread-safe implementation, using lazy initialization with double ...
Container classes are expected to implement CRUD-like methods to do the following: create an empty container (constructor); insert objects into the container; delete objects from the container; delete all the objects in the container (clear); access the objects in the container; access the number of objects in the container (count).
The class defines the data format or type (including member variables and their types) and available procedures (class methods or member functions) for a given type or class of object. Objects are created by calling a special type of method in the class known as a constructor .
reStructuredText (RST, ReST, or reST) is a file format for textual data used primarily in the Python programming language community for technical documentation.. It is part of the Docutils project of the Python Doc-SIG (Documentation Special Interest Group), aimed at creating a set of tools for Python similar to Javadoc for Java or Plain Old Documentation (POD) for Perl.