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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] |
Method (computer Science)
A method in object-oriented programming (OOP) is a procedure associated with an object, and generally also a message. An object consists of ''state data'' and ''behavior''; these compose an ''interface'', which specifies how the object may be used. A method is a behavior of an object parametrized by a user. Data is represented as properties of the object, and behaviors are represented as methods. For example, a Window object could have methods such as open and close, while its state (whether it is open or closed at any given point in time) would be a property. In class-based programming, methods are defined within a class, and objects are instances of a given class. One of the most important capabilities that a method provides is '' method overriding'' - the same name (e.g., area) can be used for multiple different kinds of classes. This allows the sending objects to invoke behaviors and to delegate the implementation of those behaviors to the receiving object. A method in Ja ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copy Constructor
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 some sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JavaWorld
''InfoWorld'' (''IW'') is an American information technology media business. Founded in 1978, it began as a monthly magazine. In 2007, it transitioned to a Web-only publication. Its parent company is International Data Group, and its sister publications include ''Macworld'' and ''PC World''. ''InfoWorld'' is based in San Francisco, with contributors and supporting staff based across the U.S. Since its founding, ''InfoWorld''s readership has largely consisted of IT and business professionals. ''InfoWorld'' focuses on how-to, analysis, and editorial content from a mixture of experienced technology journalists and working technology practitioners. The site averages 4.6 million monthly page views and 1.1 million monthly unique visitors. History The magazine was founded by Jim Warren in 1978 as ''The Intelligent Machines Journal'' (IMJ). It was sold to IDG in late 1979. On 18 February 1980, the magazine name was changed to ''InfoWorld''. In 1986, the Robert X. Cringely column beg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bitstream
A bitstream (or bit stream), also known as binary sequence, is a sequence of bits. A bytestream is a sequence of bytes. Typically, each byte is an 8-bit quantity, and so the term octet stream is sometimes used interchangeably. An octet may be encoded as a sequence of 8 bits in multiple different ways (see bit numbering) so there is no unique and direct translation between bytestreams and bitstreams. Bitstreams and bytestreams are used extensively in telecommunications and computing. For example, synchronous bitstreams are carried by SONET, and Transmission Control Protocol transports an asynchronous bytestream. Relationship to bytestreams In practice, bitstreams are not used directly to encode bytestreams; a communication channel may use a signalling method that does not directly translate to bits (for instance, by transmitting signals of multiple frequencies) and typically also encodes other information such as framing and error correction together with its data. Exa ... [...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] |
Immutable Object
In object-oriented (OO) and functional programming, an immutable object (unchangeable object) is an object whose state cannot be modified after it is created.Goetz et al. ''Java Concurrency in Practice''. Addison Wesley Professional, 2006, Section 3.4. Immutability This is in contrast to a mutable object (changeable object), which can be modified after it is created. In some cases, an object is considered immutable even if some internally used attributes change, but the object's state appears unchanging from an external point of view. For example, an object that uses to cache the results of expensive computations could still be considered an immutable object. Strings and other concrete objects are typically expressed as immutable objects to improve readability and runtime efficiency in object-oriented programming. Immutable objects are also useful because they are inherently thread-safe. Other benefits are that they are simpler to understand and reason about and offer higher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Default Constructor
Default may refer to: Law * Default (law), the failure to do something required by law ** Default (finance) In finance, default is failure to meet the legal obligations (or conditions) of a loan, for example when a home buyer fails to make a mortgage payment, or when a corporation or government fails to pay a bond which has reached maturity. A natio ..., failure to satisfy the terms of a loan obligation or failure to pay back a loan ** Default judgment, a binding judgment in favor of either party based on some failure to take action by the other party ** Default rule, a rule of law that can be overridden by a contract, trust, will, or other legally effective agreement Science, technology * Default (computer science), a preset setting or value that will be used if no choice is done during program use or installation and setup * Default password, allows the device to be accessed during its initial setup, or after resetting to factory defaults * defaults (software), a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Singleton Pattern
In object-oriented programming, the singleton pattern is a software design pattern that restricts the instantiation of a class to a singular instance. It is one of the well-known "Gang of Four" design patterns, which describe how to solve recurring problems in object-oriented software. The pattern is useful when exactly one object is needed to coordinate actions across a system. More specifically, the singleton pattern allows classes to: * Ensure they only have one instance * Provide easy access to that instance * Control their instantiation (for example, hiding the constructors of a class) The term comes from the mathematical concept of a singleton. Common uses Singletons are often preferred to global variables because they do not pollute the global namespace (or their containing namespace). Additionally, they permit lazy allocation and initialization, whereas global variables in many languages will always consume resources. The singleton pattern can also be used as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Factory Method Pattern
In object-oriented programming, the factory method pattern is a software design pattern, design pattern that uses factory methods to deal with the problem of object creation, creating objects without having to specify their exact class (computer programming), classes. Rather than by calling a Constructor (object-oriented programming), constructor, this is accomplished by invoking a factory method to create an object. Factory methods can be specified in an Interface (object-oriented programming), interface and implemented by subclasses or implemented in a base class and optionally method overriding, overridden by subclasses. It is one of the 23 classic design patterns described in the book ''Design Patterns'' (often referred to as the "Gang of Four" or simply "GoF") and is subcategorized as a creational pattern. Overview The factory method design pattern solves problems such as: * How can an object's Subclass (computer science), subclasses redefine its subsequent and distinct impleme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Covariant Return Type
In object-oriented programming, a covariant return type of a method is one that can be replaced by a "narrower" (derived) type when the method is overridden in a subclass. A notable language in which this is a fairly common paradigm is C++. C# supports return type covariance as of version 9.0. Covariant return types have been (partially) allowed in the Java language since the release of JDK5.0, were introduced to circumvent problems introduced by polymorphism and the new generic type erasure so the following example wouldn't compile on a previous release: [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java (programming Language)
Java is a High-level programming language, high-level, General-purpose programming language, general-purpose, Memory safety, memory-safe, object-oriented programming, object-oriented programming language. It is intended to let programmers ''write once, run anywhere'' (Write once, run anywhere, WORA), meaning that compiler, compiled Java code can run on all platforms that support Java without the need to recompile. Java applications are typically compiled to Java bytecode, bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax (programming languages), syntax of Java is similar to C (programming language), C and C++, but has fewer low-level programming language, low-level facilities than either of them. The Java runtime provides dynamic capabilities (such as Reflective programming, reflection and runtime code modification) that are typically not available in traditional compiled languages. Java gained popularity sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Conversion
In computer science, type conversion, type casting, type coercion, and type juggling are different ways of changing an expression from one data type to another. An example would be the conversion of an integer value into a floating point value or its textual representation as a string, and vice versa. Type conversions can take advantage of certain features of type hierarchies or data representations. Two important aspects of a type conversion are whether it happens ''implicitly'' (automatically) or ''explicitly'', and whether the underlying data representation is converted from one representation into another, or a given representation is merely ''reinterpreted'' as the representation of another data type. In general, both primitive and compound data types can be converted. Each programming language has its own rules on how types can be converted. Languages with strong typing typically do little implicit conversion and discourage the reinterpretation of representations, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
