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Declaration (computer Science)
In computer programming, a declaration is a language construct specifying identifier properties: it declares a word's (identifier's) meaning."A declaration specifies the interpretation and attributes of a set of identifiers. A ''definition'' of an identifier is a declaration for that identifier that: * for an object ariable or constant causes storage to be reserved for that object; * for a function, includes the function body; * for an enumeration constant, is the (only) declaration of the identifier; * for a typedef name, is the first (or only) declaration of the identifier." C11 specification, 6.7: Declarations, paragraph 5. Declarations are most commonly used for functions, variables, constants, and classes, but can also be used for other entities such as enumerations and type definitions. Beyond the name (the identifier itself) and the kind of entity (function, variable, etc.), declarations typically specify the data type (for variables and constants), or the type signatur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Programming
Computer programming is the process of performing a particular computation (or more generally, accomplishing a specific computing result), usually by designing and building an executable computer program. Programming involves tasks such as analysis, generating algorithms, profiling algorithms' accuracy and resource consumption, and the implementation of algorithms (usually in a chosen programming language, commonly referred to as coding). The source code of a program is written in one or more languages that are intelligible to programmers, rather than machine code, which is directly executed by the central processing unit. The purpose of programming is to find a sequence of instructions that will automate the performance of a task (which can be as complex as an operating system) on a computer, often for solving a given problem. Proficient programming thus usually requires expertise in several different subjects, including knowledge of the application domain, specialized algori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pascal (programming Language)
Pascal is an imperative and procedural programming language, designed by Niklaus Wirth as a small, efficient language intended to encourage good programming practices using structured programming and data structuring. It is named in honour of the French mathematician, philosopher and physicist Blaise Pascal. Pascal was developed on the pattern of the ALGOL 60 language. Wirth was involved in the process to improve the language as part of the ALGOL X efforts and proposed a version named ALGOL W. This was not accepted, and the ALGOL X process bogged down. In 1968, Wirth decided to abandon the ALGOL X process and further improve ALGOL W, releasing this as Pascal in 1970. On top of ALGOL's scalars and arrays, Pascal enables defining complex datatypes and building dynamic and recursive data structures such as lists, trees and graphs. Pascal has strong typing on all objects, which means that one type of data cannot be converted to or interpreted as another without explicit conversi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JavaScript
JavaScript (), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. As of 2022, 98% of Website, websites use JavaScript on the Client (computing), client side for Web page, webpage behavior, often incorporating third-party Library (computing), libraries. All major Web browser, web browsers have a dedicated JavaScript engine to execute the Source code, code on User (computing), users' devices. JavaScript is a High-level programming language, high-level, often Just-in-time compilation, just-in-time compiled language that conforms to the ECMAScript standard. It has dynamic typing, Prototype-based programming, prototype-based object-oriented programming, object-orientation, and first-class functions. It is Programming paradigm, multi-paradigm, supporting Event-driven programming, event-driven, functional programming, functional, and imperative programming, imperative programming paradigm, programmin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
One Definition Rule
The One Definition Rule (ODR) is an important rule of the C++ programming language that prescribes that classes/structs and non-inline functions cannot have more than one definition in the entire program and template and types cannot have more than one definition by translation unit. It is defined in the ISO C++ Standard (ISO/IEC 14882) 2003, at section 3.2. Summary In short, the ODR states that: #In any translation unit, a template, type, function, or object can have no more than one definition. Some of these can have any number of declarations. A definition provides an instance. #In the entire program, an object or non-inline function cannot have more than one definition; if an object or function is used, it must have exactly one definition. You can declare an object or function that is never used, in which case you don't have to provide a definition. In no event can there be more than one definition. #Some things, like types, templates, and extern inline functions, can be de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Library (computing)
In computer science, a library is a collection of non-volatile memory, non-volatile resources used by computer programs, often for software development. These may include configuration data, documentation, help data, message templates, Code reuse, pre-written code and subroutines, Class (computer science), classes, Value (computer science), values or Data type, type specifications. In OS/360 and successors, IBM's OS/360 and its successors they are referred to as Data set (IBM mainframe)#Partitioned datasets, partitioned data sets. A library is also a collection of implementations of behavior, written in terms of a language, that has a well-defined interface (computing), interface by which the behavior is invoked. For instance, people who want to write a higher-level program can use a library to make system calls instead of implementing those system calls over and over again. In addition, the behavior is provided for reuse by multiple independent programs. A program invokes the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Information Hiding
In computer science, information hiding is the principle of segregation of the ''design decisions'' in a computer program that are most likely to change, thus protecting other parts of the program from extensive modification if the design decision is changed. The protection involves providing a stable interface which protects the remainder of the program from the implementation (whose details are likely to change). Written in another way, information hiding is the ability to prevent certain aspects of a class or software component from being accessible to its clients, using either programming language features (like private variables) or an explicit exporting policy. Overview The term ''encapsulation'' is often used interchangeably with information hiding. Not all agree on the distinctions between the two, though; one may think of information hiding as being the principle and encapsulation being the technique. A software module hides information by encapsulating the information ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java 8
The Java (programming language), Java language has undergone several changes since Java Development Kit, JDK 1.0 as well as numerous additions of class (computer science), classes and packages to the standard library (computer science), library. Since J2SE 1.4, the evolution of the Java language has been governed by the Java Community Process (JCP), which uses ''Java Specification Requests'' (JSRs) to propose and specify additions and changes to the Java platform. The language is specified by the ''Java Language Specification'' (JLS); changes to the JLS are managed undeJSR 901 In September 2017, Mark Reinhold, chief Architect of the Java Platform, proposed to change the release train to "one feature release every six months" rather than the then-current two-year schedule. This proposal took effect for all following versions, and is still the current release schedule. In addition to the language changes, other changes have been made to the Java Class Library over t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instance (computer Science)
In a computer system, any time a new context is created based on some model, it is said that the model has been instantiated. In practice, this instance usually has a data structure in common with other instances, but the values stored in the instances are separate. Changing the values in one instance will then not interfere with the values of some other instance. A compute instance can be software or hardware which can run code, for example a CPU, GPU or a virtual machine. Computer graphics In computer graphics, a polygonal model can be instantiated in order to be drawn several times in different locations in a scene. This is a technique that can be used to improve the performance of rendering, since the work needed to display each instance overlaps. Object-oriented programming In object-oriented programming (OOP), an instance is a concrete occurrence of any object, existing usually during the runtime of a computer program. Formally, "instance" is synonymous with "object" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abstract Method
A method in object-oriented programming (OOP) is a Procedure (computer science), procedure associated with a Message passing, message and an Object (computer science), object. An object consists of ''state data'' and ''behavior''; these compose an Interface (computing), ''interface'', which specifies how the object may be utilized by any of its various consumers. A method is a behavior of an object parametrized by a consumer. Data is represented as Property (programming), 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 (computer science), class, and objects are Instance (computer science), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Function Prototype
In computer programming, a function prototype or function interface is a declaration of a function that specifies the function’s name and type signature (arity, data types of parameters, and return type), but omits the function body. While a function definition specifies ''how'' the function does what it does (the "implementation"), a function prototype merely specifies its interface, i.e. ''what'' data types go in and come out of it. The term "function prototype" is particularly used in the context of the programming languages C and C++ where placing forward declarations of functions in header files allows for splitting a program into translation units, i.e. into parts that a compiler can separately translate into object files, to be combined by a linker into an executable or a library. In a prototype, parameter names are optional (and in C/C++ have function prototype scope, meaning their scope ends at the end of the prototype), however, the type is necessary along with all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Source File
In computing, source code, or simply code, is any collection of code, with or without comments, written using a human-readable programming language, usually as plain text. The source code of a program is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source code. The source code is often transformed by an assembler or compiler into binary machine code that can be executed by the computer. The machine code is then available for execution at a later time. Most application software is distributed in a form that includes only executable files. If the source code were included it would be useful to a user, programmer or a system administrator, any of whom might wish to study or modify the program. Alternatively, depending on the technology being used, source code may be interpreted and executed directly. Definitions Richard Stallman's definition, formulated in his 1989 seminal licen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Header File
Many programming languages and other computer files have a directive, often called include (sometimes copy or import), that causes the contents of the specified file to be inserted into the original file. These included files are called copybooks or s. There are over one thousand C library files and they are often used to define the physical layout of program data, pieces of procedural code, and/or forward declarations while promoting encapsulation and the reuse of code or data. Header files In computer programming, a header file is a file that allows programmers to separate certain elements of a program's source code into reusable files. Header files commonly contain forward declarations of classes, subroutines, variables, and other identifiers. Programmers who wish to declare standardized identifiers in more than one source file can place such identifiers in a single header file, which other code can then include whenever the header contents are required. This is to keep the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
