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Value Object
In computer science, a value object is a small object that represents a ''simple'' entity whose equality is not based on identity: i.e. two value objects are ''equal'' when they ''have'' the same ''value'', not necessarily being the ''same object''. Examples of value objects are objects representing an amount of money or a date range. Being small, one can have multiple copies of the same value object that represent the same ''entity'': it is often simpler to create a new object rather than rely on a single instance and use references to it. Value objects should be immutable: this is required for the implicit contract that two value objects created ''equal'', should remain equal. It is also useful for value objects to be immutable, as client code cannot put the value object in an invalid state or introduce buggy behaviour after instantiation. Value objects are among the building blocks of DDD. Implementation Due to the nuances of various object-oriented programming languages, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Science
Computer science is the study of computation, information, and automation. Computer science spans Theoretical computer science, theoretical disciplines (such as algorithms, theory of computation, and information theory) to Applied science, applied disciplines (including the design and implementation of Computer architecture, hardware and Software engineering, software). Algorithms and data structures are central to computer science. The theory of computation concerns abstract models of computation and general classes of computational problem, problems that can be solved using them. The fields of cryptography and computer security involve studying the means for secure communication and preventing security vulnerabilities. Computer graphics (computer science), Computer graphics and computational geometry address the generation of images. Programming language theory considers different ways to describe computational processes, and database theory concerns the management of re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Struct (C Programming Language)
In the C programming language, struct is the keyword used to define a composite, a.k.a. record, data type a named set of values that occupy a block of memory. It allows for the different values to be accessed via a single identifier, often a pointer. A struct can contain other data types so is used for mixed-data-type records. For example a bank customer struct might contains fields: name, address, telephone, balance. A struct occupies a ''contiguous block'' of memory, usually delimited (sized) by word-length boundaries. It corresponds to the similarly named feature available in some assemblers for Intel processors. Being a block of contiguous memory, each field within a struct is located at a certain fixed offset from the start. The sizeof operator results in the number of bytes needed to store a particular struct, just as it does for a primitive data type. The alignment of particular fields in the struct (with respect to word boundaries) is implementation-specific and may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Transfer Object
In the field of programming a data transfer object (DTOMSDN (2010). Data Transfer Object. Microsoft MSDN Library. Retrieved from https://msdn.microsoft.com/en-us/library/ms978717.aspx.Fowler, Martin (2010). Data Transfer Object. Patterns of Enterprise Application Architecture. Retrieved from http://martinfowler.com/eaaCatalog/dataTransferObject.html.) is an object that carries data between processes. The motivation for its use is that communication between processes is usually done resorting to remote interfaces (e.g., web services), where each call is an expensive operation. Because the majority of the cost of each call is related to the round-trip time between the client and the server, one way of reducing the number of calls is to use an object (the DTO) that aggregates the data that would have been transferred by the several calls, but that is served by one call only. The difference between data transfer objects and business objects or data access objects is that a DTO does no ... [...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] |
Blank Final
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] |
Python (programming Language)
Python is a high-level programming language, high-level, general-purpose programming language. Its design philosophy emphasizes code readability with the use of significant indentation. Python is type system#DYNAMIC, dynamically type-checked and garbage collection (computer science), garbage-collected. It supports multiple programming paradigms, including structured programming, structured (particularly procedural programming, procedural), object-oriented and functional programming. It is often described as a "batteries included" language due to its comprehensive standard library. Guido van Rossum began working on Python in the late 1980s as a successor to the ABC (programming language), ABC programming language, and he first released it in 1991 as Python 0.9.0. Python 2.0 was released in 2000. Python 3.0, released in 2008, was a major revision not completely backward-compatible with earlier versions. Python 2.7.18, released in 2020, was the last release of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Const-correctness
In some programming languages, const is a type qualifier (a keyword applied to a data type) that indicates that the data is read-only. While this can be used to declare constants, in the C family of languages differs from similar constructs in other languages in that it is part of the ''type'', and thus has complicated behavior when combined with pointers, references, composite data types, and type-checking. In other languages, the data is not in a single memory location, but copied at compile time for each use. Languages which use it include C, C++, D, JavaScript, Julia, and Rust. Introduction When applied in an object declaration, it indicates that the object is a constant: its value may not be changed, unlike a variable. This basic use – to declare constants – has parallels in many other languages. However, unlike in other languages, in the C family of languages the const is part of the ''type'', not part of the ''object''. For example, in C, declar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assignment Operator (C++)
Assignment, assign or The Assignment may refer to: * Homework * Sex assignment * The process of sending National Basketball Association players to its development league; see Computing * Assignment (computer science), a type of modification to a variable * Drive letter assignment, the process of assigning alphabetical identifiers to disk drives or partitions * ASSIGN (DOS command) Mathematics * Assignment problem, a type of math problem * Assignment (mathematical logic) Financial and legal * Assignment (housing law), a concept that allows the transfer of a tenancy from one person to another * Assignment (law) Assignment is a legal term used in the context of the laws of contract and of property. In both instances, assignment is the process whereby a person, the ''assignor'', transfers rights or benefits to another, the ''assignee''.For the assignment ..., a transfer of rights between two parties * Along with clearing, a stage in exercising a financial option * General ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operator Overloading
In computer programming, operator overloading, sometimes termed ''operator ad hoc polymorphism'', is a specific case of polymorphism, where different operators have different implementations depending on their arguments. Operator overloading is generally defined by a programming language, a programmer, or both. Rationale Operator overloading is syntactic sugar, and is used because it allows programming using notation nearer to the target domain and allows user-defined types a similar level of syntactic support as types built into a language. It is common, for example, in scientific computing, where it allows computing representations of mathematical objects to be manipulated with the same syntax as on paper. Operator overloading does not change the expressive power of a language (with functions), as it can be emulated using function calls. For example, consider variables , and of some user-defined type, such as matrices: In a language that supports operator overloadin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operator Overload
In computer programming, operator overloading, sometimes termed ''operator ad hoc polymorphism'', is a specific case of polymorphism, where different operators have different implementations depending on their arguments. Operator overloading is generally defined by a programming language, a programmer, or both. Rationale Operator overloading is syntactic sugar, and is used because it allows programming using notation nearer to the target domain and allows user-defined types a similar level of syntactic support as types built into a language. It is common, for example, in scientific computing, where it allows computing representations of mathematical objects to be manipulated with the same syntax as on paper. Operator overloading does not change the expressive power of a language (with functions), as it can be emulated using function calls. For example, consider variables , and of some user-defined type, such as matrices: In a language that supports operator overloading, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Business Logic
In computer software, business logic or domain logic is the part of the program that encodes the real-world business rules that determine how data can be created, stored, and changed. It is contrasted with the remainder of the software that might be concerned with lower-level details of managing a database or displaying the user interface, system infrastructure, or generally connecting various parts of the program. Details and example Business logic: * Prescribes how business objects interact with one another * Enforces the routes and the methods by which business objects are accessed and updated Business rules: * Model real-life business objects (such as accounts, loans, itineraries, and inventories) Business logic comprises: * Workflows that are the ordered tasks of passing documents or data from one participant (a person or a software system) to another. Business logic should be distinguished from business rules. Business logic is the portion of an enterprise system which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C Sharp Syntax
This article describes the syntax of the C# programming language. The features described are compatible with .NET Framework and Mono. Basics Identifier An identifier is the name of an element in the code. It can contain letters, digits and underscores (_), and is case sensitive (FOO is different from foo). The language imposes the following restrictions on identifier names: * They cannot start with a digit; * They cannot start with a symbol, unless it is a keyword; * They cannot contain more than 511 characters. Identifier names may be prefixed by an at sign (@), but this is insignificant; @name is the same identifier as name. Microsoft has published naming conventions for identifiers in C#, which recommend the use of PascalCase for the names of types and most type members, and camelCase for variables and for private or internal fields. However, these naming conventions are not enforced in the language. Keywords Keywords are predefined reserved words with special syntact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
