|
Collection (abstract Data Type)
In computer programming, a collection is an abstract data type that is a grouping of items that can be used in a Polymorphism (computer science), polymorphic way. Often, the items are of the same data type such as Integer (computer science), int or String (computer science), string. Sometimes the items derive from a common type; even deriving from the most general type of a programming language such as Object (computer science), object or Variant type (COM), variant. Although easily confused with implementations in programming languages, collection, as an abstract concept, refers to mathematical concepts which can be misunderstood when the focus is on an implementation. For example, a priority queue is often implemented as a heap, while an associative array is often implemented as a hash table, so these abstract types are often referred to by this preferred implementation, as a "heap" or a "hash", though this is incorrect conceptually. Subtypes Other abstract data types are more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 procedures, by writing source code, code in one or more programming languages. Programmers typically use high-level programming languages that are more easily intelligible to humans than machine code, which is directly executed by the central processing unit. Proficient programming usually requires expertise in several different subjects, including knowledge of the Domain (software engineering), application domain, details of programming languages and generic code library (computing), libraries, specialized algorithms, and Logic#Formal logic, formal logic. Auxiliary tasks accompanying and related to programming include Requirements analysis, analyzing requirements, Software testing, testing, debugging (investigating and fixing problems), imple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiset (abstract Data Type)
In computer science, a set is an abstract data type that can store unique values, without any particular order. It is a computer implementation of the mathematical concept of a finite set. Unlike most other collection types, rather than retrieving a specific element from a set, one typically tests a value for membership in a set. Some set data structures are designed for static or frozen sets that do not change after they are constructed. Static sets allow only query operations on their elements — such as checking whether a given value is in the set, or enumerating the values in some arbitrary order. Other variants, called dynamic or mutable sets, allow also the insertion and deletion of elements from the set. A multiset is a special kind of set in which an element can appear multiple times in the set. Type theory In type theory, sets are generally identified with their indicator function (characteristic function): accordingly, a set of values of type A may be denoted by 2^ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PL/SQL
PL/SQL (Procedural Language for SQL) is Oracle Corporation's procedural extension for SQL and the Oracle relational database. PL/SQL is available in Oracle Database (since version 6 - stored PL/SQL procedures/functions/packages/triggers since version 7), TimesTen in-memory database (since version 11.2.1), and IBM Db2 (since version 9.7). Oracle Corporation usually extends PL/SQL functionality with each successive release of the Oracle Database. PL/SQL includes procedural language elements such as conditions and loops, and can handle exceptions (run-time errors). It allows the declaration of constants and variables, procedures, functions, packages, types and variables of those types, and triggers. Arrays are supported involving the use of PL/SQL collections. Implementations from version 8 of Oracle Database onwards have included features associated with object-orientation. One can create PL/SQL units such as procedures, functions, packages, types, and triggers, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Collections Framework
The Java collections framework is a set of classes and interfaces that implement commonly reusable collection data structures. Although referred to as a framework, it works in a manner of a library. The collections framework provides both interfaces that define various collections and classes that implement them. Differences from Arrays Collections and arrays are similar in that they both hold references to objects and they can be managed as a group. However, unlike arrays, Collections do not need to be assigned a certain capacity when instantiated. Collections can grow and shrink in size automatically when objects are added or removed. Collections cannot hold primitive data types such as int, long, or double. Instead, Collections can hold wrapper classes such as , , or . Collections are generic and hence invariant, but arrays are covariant. This can be considered an advantage of generic objects such as when compared to arrays, because under circumstances, using the gener ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Template Library
The Standard Template Library (STL) is a software library originally designed by Alexander Stepanov for the C++ programming language that influenced many parts of the C++ Standard Library. It provides four components called ''algorithms'', ''containers'', '' functors'', and ''iterators''. The STL provides a set of common classes for C++, such as containers and associative arrays, that can be used with any built-in type or user-defined type that supports some elementary operations (such as copying and assignment). STL algorithms are independent of containers, which significantly reduces the complexity of the library. The STL achieves its results through the use of templates. This approach provides compile-time polymorphism that is often more efficient than traditional run-time polymorphism. Modern C++ compilers are tuned to minimize abstraction penalties arising from heavy use of the STL. The STL was created as the first library of generic algorithms and data structures f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C++ Standard Library
The C standard library, sometimes referred to as libc, is the standard library for the C programming language, as specified in the ISO C standard.ISO/ IEC (2018). '' ISO/IEC 9899:2018(E): Programming Languages - C §7'' Starting from the original ANSI C standard, it was developed at the same time as the C POSIX library, which is a superset of it. Since ANSI C was adopted by the International Organization for Standardization, the C standard library is also called the ISO C library. The C standard library provides macros, type definitions and functions for tasks such as string manipulation, mathematical computation, input/output processing, memory management, and input/output. Application programming interface (API) Header files The application programming interface (API) of the C standard library is declared in a number of header files. Each header file contains one or more function declarations, data type definitions, and macros. After a long period of stability, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Library
In computer programming, a standard library is the library (computing), library made available across Programming language implementation, implementations of a programming language. Often, a standard library is specified by its associated programming language specification, however, some are set in part or whole by more informal practices of a language community. Some languages define a core part of the standard library that must be made available in all implementations while allowing other parts to be implemented optionally. As defined with the core language aspects, the line between the core language and its standard library is relatively subtle. A programmer may confuse the two aspects even though the language designers intentionally separate the two. The line between the core language and its standard library is further blurred in some languages by defining core language constructs in terms of its standard library. For example, Java (programming language), Java defines a str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Composite Data Type
In computer science, a composite data type or compound data type is a data type that consists of programming language scalar data types and other composite types that may be heterogeneous and hierarchical in nature. It is sometimes called a structure or a record or by a language-specific keyword used to define one such as struct. It falls into the aggregate type classification which includes homogenous collections such as the array and list A list is a Set (mathematics), set of discrete items of information collected and set forth in some format for utility, entertainment, or other purposes. A list may be memorialized in any number of ways, including existing only in the mind of t .... See also * * * * References {{Data types Data types Type theory Articles with example C code Articles with example C++ code ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primitive Data Type
In computer science, primitive data types are a set of basic data types from which all other data types are constructed. Specifically it often refers to the limited set of data representations in use by a particular processor, which all compiled programs must use. Most processors support a similar set of primitive data types, although the specific representations vary. More generally, ''primitive data types'' may refer to the standard data types built into a programming language (built-in types). Data types which are not primitive are referred to as ''derived'' or ''composite''. Primitive types are almost always value types, but composite types may also be value types. Common primitive data types The most common primitive types are those used and supported by computer hardware, such as integers of various sizes, floating-point numbers, and Boolean logical values. Operations on such types are usually quite efficient. Primitive data types which are native to the processor have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Container (type Theory)
In type theory, a discipline within mathematical logic, containers are abstractions which permit various "collection types", such as lists and trees, to be represented in a uniform way. A ( unary) container is defined by a type of ''shapes'' S and a type family of ''positions'' P, indexed by S. The ''extension'' of a container is a family of dependent pairs consisting of a shape (of type S) and a function from positions of that shape to the element type. Containers can be seen as canonical forms for collection types. For lists, the shape type is the natural numbers (including zero). The corresponding position types are the types of natural numbers less than the shape, for each shape. For trees, the shape type is the type of trees of units (that is, trees with no information in them, just structure). The corresponding position types are isomorphic to the types of valid paths from the root to particular nodes on the shape, for each shape. Note that the natural numbers are isomorphic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Theory
In mathematics and theoretical computer science, a type theory is the formal presentation of a specific type system. Type theory is the academic study of type systems. Some type theories serve as alternatives to set theory as a foundation of mathematics. Two influential type theories that have been proposed as foundations are: * Typed λ-calculus of Alonzo Church * Intuitionistic type theory of Per Martin-Löf Most computerized proof-writing systems use a type theory for their foundation. A common one is Thierry Coquand's Calculus of Inductive Constructions. History Type theory was created to avoid paradoxes in naive set theory and formal logic, such as Russell's paradox which demonstrates that, without proper axioms, it is possible to define the set of all sets that are not members of themselves; this set both contains itself and does not contain itself. Between 1902 and 1908, Bertrand Russell proposed various solutions to this problem. By 1908, Russell arrive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indicator Function
In mathematics, an indicator function or a characteristic function of a subset of a set is a function that maps elements of the subset to one, and all other elements to zero. That is, if is a subset of some set , then the indicator function of is the function \mathbf_A defined by \mathbf_\!(x) = 1 if x \in A, and \mathbf_\!(x) = 0 otherwise. Other common notations are and \chi_A. The indicator function of is the Iverson bracket of the property of belonging to ; that is, \mathbf_(x) = \left x\in A\ \right For example, the Dirichlet function is the indicator function of the rational numbers as a subset of the real numbers. Definition Given an arbitrary set , the indicator function of a subset of is the function \mathbf_A \colon X \mapsto \ defined by \operatorname\mathbf_A\!( x ) = \begin 1 & \text x \in A \\ 0 & \text x \notin A \,. \end The Iverson bracket provides the equivalent notation \left x\in A\ \right/math> or that can be used instead of \mathbf_\ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
