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Object Copying
In object-oriented programming, object copying is creating a copy of an existing object, a unit of data in object-oriented programming. The resulting object is called an ''object copy'' or simply ''copy'' of the original object. Copying is basic but has subtleties and can have significant overhead. There are several ways to copy an object, most commonly by a copy constructor or cloning. Copying is done mostly so the copy can be modified or moved, or the current value preserved. If either of these is unneeded, a reference to the original data is sufficient and more efficient, as no copying occurs. Objects in general store composite data. While in simple cases copying can be done by allocating a new, uninitialized object and copying all fields (attributes) from the original object, in more complex cases this does not result in desired behavior. Methods of copying The design goal of most objects is to give the resemblance of being made out of one monolithic block even though most a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object-oriented Programming
Object-oriented programming (OOP) is a programming paradigm based on the concept of '' objects''. Objects can contain data (called fields, attributes or properties) and have actions they can perform (called procedures or methods and implemented in code). In OOP, computer programs are designed by making them out of objects that interact with one another. Many of the most widely used programming languages (such as C++, Java, and Python) support object-oriented programming to a greater or lesser degree, typically as part of multiple paradigms in combination with others such as imperative programming and declarative programming. Significant object-oriented languages include Ada, ActionScript, C++, Common Lisp, C#, Dart, Eiffel, Fortran 2003, Haxe, Java, JavaScript, Kotlin, Logo, MATLAB, Objective-C, Object Pascal, Perl, PHP, Python, R, Raku, Ruby, Scala, SIMSCRIPT, Simula, Smalltalk, Swift, Vala and Visual Basic.NET. History The idea of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clone (Java Method)
clone() is a method in the Java programming language for object duplication. In Java, objects are manipulated through reference variables, and there is no operator for ''copying'' an object—the assignment operator duplicates the reference, not the object. The clone() method provides this missing functionality. Overview Classes that want copying functionality must implement some method to do so. To a certain extent that function is provided by "Object.clone()". clone() acts like a copy constructor. Typically it calls the clone() method of its superclass to obtain the copy, etc. until it eventually reaches Object's clone() method. The special clone() method in the base class Object provides a standard mechanism for duplicating objects. The class Object's clone() method creates and returns a copy of the object, with the same class and with all the fields having the same values. However, Object.clone() throws a CloneNotSupportedException unless the object is an instance of a cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C Sharp (programming Language)
C# ( pronounced: C-sharp) ( ) is a general-purpose high-level programming language supporting multiple paradigms. C# encompasses static typing, strong typing, lexically scoped, imperative, declarative, functional, generic, object-oriented (class-based), and component-oriented programming disciplines. The principal inventors of the C# programming language were Anders Hejlsberg, Scott Wiltamuth, and Peter Golde from Microsoft. It was first widely distributed in July 2000 and was later approved as an international standard by Ecma (ECMA-334) in 2002 and ISO/ IEC (ISO/IEC 23270 and 20619) in 2003. Microsoft introduced C# along with .NET Framework and Microsoft Visual Studio, both of which are technically speaking, closed-source. At the time, Microsoft had no open-source products. Four years later, in 2004, a free and open-source project called Microsoft Mono began, providing a cross-platform compiler and runtime environment for the C# programming language. A decad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Storage
In computer programming Computer programming or coding is the composition of sequences of instructions, called computer program, programs, that computers can follow to perform tasks. It involves designing and implementing algorithms, step-by-step specifications of proc ..., a reference is a value that enables a program to indirectly access a particular datum, such as a variable (computer science), variable's value or a record (computer science), record, in the computer's memory (computing), memory or in some other Data storage device, storage device. The reference is said to refer to the datum, and accessing the datum is called Dereference operator, dereferencing the reference. A reference is distinct from the datum itself. A reference is an abstract data type and may be implemented in many ways. Typically, a reference refers to data stored in memory on a given system, and its internal value is the memory address of the data, i.e. a reference is implemented as a Pointer (com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eiffel (programming Language)
Eiffel is an object-oriented programming language designed by Bertrand Meyer (an object-orientation proponent and author of '' Object-Oriented Software Construction'') and Eiffel Software. Meyer conceived the language in 1985 with the goal of increasing the reliability of commercial software development. The first version was released in 1986. In 2005, the International Organization for Standardization (ISO) released a technical standard for Eiffel. The design of the language is closely connected with the Eiffel programming method. Both are based on a set of principles, including design by contract, command–query separation, the uniform-access principle, the single-choice principle, the open–closed principle, and option–operand separation. Many concepts initially introduced by Eiffel were later added into Java, C#, and other languages. New language design ideas, particularly through the Ecma/ ISO standardization process, continue to be incorporated into the Eiffe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Final (Java)
In the Java programming language, the final keyword is used in several contexts to define an entity that can only be assigned once. Once a final variable has been assigned, it always contains the same value. If a final variable holds a reference to an object, then the state of the object may be changed by operations on the object, but the variable will always refer to the same object (this property of final is called ''non-transitivity''). This applies also to arrays, because arrays are objects; if a final variable holds a reference to an array, then the components of the array may be changed by operations on the array, but the variable will always refer to the same array. Final classes A final class cannot be subclassed. As doing this can confer security and efficiency benefits, many of the Java standard library classes are final, such as and . Example: public final class MyFinalClass public class ThisIsWrong extends MyFinalClass // forbidden Final methods A final metho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constructor (computer Science)
In class-based, object-oriented programming, a constructor (abbreviation: ctor) is a special type of function called to create an object. It prepares the new object for use, often accepting arguments that the constructor uses to set required member variables. A constructor resembles an instance method, but it differs from a method in that it has no explicit return type, it is not implicitly inherited and it usually has different rules for scope modifiers. Constructors often have the same name as the declaring class. They have the task of initializing the object's data members and of establishing the invariant of the class, failing if the invariant is invalid. A properly written constructor leaves the resulting object in a ''valid'' state. Immutable objects must be initialized in a constructor. Most languages allow overloading the constructor in that there can be more than one constructor for a class, with differing parameters. Some languages take consideration of s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wire Protocol
In computer networking, a wire protocol refers to a way of getting data from point to point: A wire protocol is needed if more than one application has to interoperate. It generally refers to communication protocols higher than the physical layer. In contrast to transport protocols at the transport level (like TCP or UDP), the term ''wire protocol'' is used to describe a common way to exchange information at the application level. It refers to an application layer protocol and defines all the required attributes for the data exchange, like data types (units of data, message formats, etc.), communication endpoints and capabilities (such as delivery guarantees, direction of communication, etc.). Usually, the data is represented at the application level as a common infoset (e.g. XML, JSON, YAML) and requires a mechanism of data binding (using e.g. a common encoding scheme like XSD). The wire protocol may be either text-based or a binary protocol. Although an important architectura ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Persistence (computer Science)
In computer science, persistence refers to the characteristic of State (computer science), state of a system that outlives (persists for longer than) the Process (computing), process that created it. This is achieved in practice by storing the state as data in computer data storage. Programs have to transfer data to and from storage devices and have to provide mappings from the native Programming language, programming-language Data structure, data structures to the storage device data structures. Picture editing programs or Word processor, word processors, for example, achieve State (computer science), state persistence by saving their documents to computer file, files. Orthogonal or transparent persistence Persistence is said to be "Orthogonality#Computer science, orthogonal" or "transparent" when it is implemented as an intrinsic property of the execution environment of a program. An orthogonal persistence environment does not require any specific actions by programs running i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serialization
In computing, serialization (or serialisation, also referred to as pickling in Python (programming language), Python) is the process of translating a data structure or object (computer science), object state into a format that can be stored (e.g. computer file, files in secondary storage devices, data buffers in primary storage devices) or transmitted (e.g. data streams over computer networks) and reconstructed later (possibly in a different computer environment). When the resulting series of bits is reread according to the serialization format, it can be used to create a semantically identical clone of the original object. For many complex objects, such as those that make extensive use of reference (computer science), references, this process is not straightforward. Serialization of object (computer science), objects does not include any of their associated Method (computer science), methods with which they were previously linked. This process of serializing an object is also c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abstract Class
In object-oriented programming, a class defines the shared aspects of objects created from the class. The capabilities of a class differ between programming languages, but generally the shared aspects consist of state ( variables) and behavior ( methods) that are each either associated with a particular object or with all objects of that class. Object state can differ between each instance of the class whereas the class state is shared by all of them. The object methods include access to the object state (via an implicit or explicit parameter that references the object) whereas class methods do not. If the language supports inheritance, a class can be defined based on another class with all of its state and behavior plus additional state and behavior that further specializes the class. The specialized class is a ''sub-class'', and the class it is based on is its ''superclass''. Attributes Object lifecycle As an instance of a class, an object is constructed from a class via '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interface (object-oriented Programming)
In object-oriented programming, an interface or protocol type is a data type that acts as an abstraction of a Class (computer science), class. It describes a set of method signatures, the implementations of which may be provided by multiple class (computer programming), classes that are otherwise not necessarily related to each other. A class which provides the methods listed in an interface is said to ''implement'' the interface, or to ''adopt'' the protocol. Examples If objects are fully encapsulation (object-oriented programming), encapsulated then the interface is the only way in which they may be accessed by other objects. For example, in Java (programming language), Java, the Comparable interface specifies a method compareTo() which implementing classes must implement. This means that a sorting method, for example, can sort a collection of any objects of types which implement the Comparable interface, without having to know anything about the inner nature of the class (excep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
