# Category: Data types

Ordinal tree
An ordinal tree, by analogy with an ordinal number, is a rooted tree of arbitrary degree in which the children of each node are ordered, so that one refers to the ith child in the sequence of children
4D vector
In computer science, a 4D vector is a 4-component vector data type. Uses include homogeneous coordinates for 3-dimensional space in computer graphics, and red green blue alpha (RGBA) values for bitmap
Set (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
Union type
In computer science, a union is a value that may have any of several representations or formats within the same position in memory; that consists of a variable that may hold such a data structure. Som
HRESULT
HRESULT is a computer programming data type that represents the completion status of a function. It is used in the source code of applications targeting Microsoft Windows and earlier IBM/Microsoft OS/
Long double
In C and related programming languages, long double refers to a floating-point data type that is often more precise than double precision though the language standard only requires it to be at
Quotient type
In type theory, a kind of foundation of mathematics, a quotient type is an algebraic data type that represents a type whose equality relation has been redefined by a given equivalence relation such th
Recursive data type
In computer programming languages, a recursive data type (also known as a recursively-defined, inductively-defined or inductive data type) is a data type for values that may contain other values of th
Binary large object
A binary large object (BLOB or blob) is a collection of binary data stored as a single entity. Blobs are typically images, audio or other multimedia objects, though sometimes binary executable code is
IA5STRING
A IA5String is a restricted character string type in the ASN.1 notation.It is used to represent ISO 646 (IA5) characters. According to the ITU-T Rec. X.680 (ASN.1 Specification of basic notation) the
Function type
In computer science and mathematical logic, a function type (or arrow type or exponential) is the type of a variable or parameter to which a function has or can be assigned, or an argument or result t
K-d tree
In computer science, a k-d tree (short for k-dimensional tree) is a space-partitioning data structure for organizing points in a k-dimensional space. k-d trees are a useful data structure for several
Boolean data type
In computer science, the Boolean (sometimes shortened to Bool) is a data type that has one of two possible values (usually denoted true and false) which is intended to represent the two truth values o
Associative array
In computer science, an associative array, map, symbol table, or dictionary is an abstract data type that stores a collection of (key, value) pairs, such that each possible key appears at most once in
Abstract data type
In computer science, an abstract data type (ADT) is a mathematical model for data types. An abstract data type is defined by its behavior (semantics) from the point of view of a user, of the data, spe
Bottom type
In type theory, a theory within mathematical logic, the bottom type of a type system is the type that is a subtype of all other types. Where such a type exists, it is often represented with the up tac
Abstract graphical data type
An abstract graphical data type (AGDT) is an extension of an abstract data type for computer graphics. AGDTs provide the advantages of the ADTs with facilities to build graphical objects in a structur
Decimal data type
Some programming languages (or compilers for them) provide a built-in (primitive) or library decimal data type to represent non-repeating decimal fractions like 0.3 and -1.17 without rounding, and to
Weak symbol
A weak symbol denotes a specially annotated symbol during linking of Executable and Linkable Format (ELF) object files. By default, without any annotation, a symbol in an object file is strong. During
Flow-sensitive typing
In programming language theory, flow-sensitive typing (also called flow typing or occurrence typing) is a type system where the type of an expression depends on its position in the control flow. In st
Type system
In computer programming, a type system is a logical system comprising a set of rules that assigns a property called a type to every "term" (a word, phrase, or other set of symbols). Usually the terms
Nominative and structural type systems
No description available.
Character literal
A character literal is a type of literal in programming for the representation of a single character's value within the source code of a computer program. Languages that have a dedicated character dat
Bit
The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. Th
Numerical tower
In Scheme and in Lisp dialects inspired by it, the numerical tower is a set of data types that represent numbers and a logic for their hierarchical organisation. Each type in the tower conceptually "s
Va list
No description available.
Tagged union
In computer science, a tagged union, also called a variant, variant record, choice type, discriminated union, disjoint union, sum type or coproduct, is a data structure used to hold a value that could
Record (computer science)
In computer science, a record (also called a structure, struct, or compound data) is a basic data structure. Records in a database or spreadsheet are usually called "rows". A record is a collection of
Tryte
No description available.
Augmented map
In computer science, the augmented map is an abstract data type (ADT) based on ordered maps, which associates each ordered map an augmented value. For an ordered map with key type , comparison functio
Boxing (computer science)
In computer science, boxing (a.k.a. wrapping) is the transformation of placing a primitive type within an object so that the value can be used as a reference. Unboxing is the reverse transformation of
LOTS (personality psychology)
LOTS is an acronym, suggested by Cattell in 1957 and later elaborated by Block, to provide a broad classification of data source for personality psychology assessment. Each data source has its advanta
Kind (type theory)
In the area of mathematical logic and computer science known as type theory, a kind is the type of a type constructor or, less commonly, the type of a higher-order type operator. A kind system is esse
Type class
In computer science, a type class is a type system construct that supports ad hoc polymorphism. This is achieved by adding constraints to type variables in parametrically polymorphic types. Such a con
Character large object
A Character Large OBject (or CLOB) is part of the SQL:1999 standard data types. It is a collection of character data in a database management system, usually stored in a separate location that is refe
Enumerated type
In computer programming, an enumerated type (also called enumeration, enum, or factor in the R programming language, and a categorical variable in statistics) is a data type consisting of a set of nam
Signedness
In computing, signedness is a property of data types representing numbers in computer programs. A numeric variable is signed if it can represent both positive and negative numbers, and unsigned if it
Typing environment
In type theory a typing environment (or typing context) represents the association between variable names and data types. More formally an environment is a set or ordered list of pairs , usually writt
Pointer (computer programming)
In computer science, a pointer is an object in many programming languages that stores a memory address. This can be that of another value located in computer memory, or in some cases, that of memory-m
List of binary codes
This is a list of some binary codes that are (or have been) used to represent text as a sequence of binary digits "0" and "1". Fixed-width binary codes use a set number of bits to represent each chara
Byte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this
Variable (computer science)
In computer programming, a variable is an abstract storage location paired with an associated symbolic name, which contains some known or unknown quantity of information referred to as a value; or in
Top type
In mathematical logic and computer science, some type theories and type systems include a top type that is commonly denoted with top or the symbol ⊤. The top type is sometimes called also universal ty
Unit type
In the area of mathematical logic and computer science known as type theory, a unit type is a type that allows only one value (and thus can hold no information). The carrier (underlying set) associate
Subtyping
In programming language theory, subtyping (also subtype polymorphism or inclusion polymorphism) is a form of type polymorphism in which a subtype is a datatype that is related to another datatype (the
Composite data type
In computer science, a composite data type or compound data type is any data type which can be constructed in a program using the programming language's primitive data types and other composite types.
In IBM System/360 through present day z/Architecture, an address constant or "adcon" is an assembly language data type which contains the address of a location in computer memory. An address constant
Handle (computing)
In computer programming, a handle is an abstract reference to a resource that is used when application software references blocks of memory or objects that are managed by another system like a databas
ISO/IEC 11404
ISO/IEC 11404, General Purpose Datatypes (GPD), are a collection of datatypes defined independently of any particular programming language or implementation. These datatypes can be used to describe in
Intersection type
In type theory, an intersection type can be allocated to values that can be assigned both the type and the type . This value can be given the intersection type in an intersection type system.Generally
Integer (computer science)
In computer science, an integer is a datum of integral data type, a data type that represents some range of mathematical integers. Integral data types may be of different sizes and may or may not be a
Rational data type
Some programming languages provide a built-in (primitive) rational data type to represent rational numbers like 1/3 and -11/17 without rounding, and to do arithmetic on them. Examples are the ratio ty
Generalized algebraic data type
In functional programming, a generalized algebraic data type (GADT, also first-class phantom type, guarded recursive datatype, or equality-qualified type) is a generalization of parametric algebraic d
Soft reference
A soft reference is a reference that is garbage-collected less aggressively. The soft reference is one of the strengths or levels of 'non strong' reference defined in the Java programming language, th
Real data type
A real data type is a data type used in a computer program to represent an approximation of a real number.Because the real numbers are not countable, computers cannot represent them exactly using a fi
Algebraic data type
In computer programming, especially functional programming and type theory, an algebraic data type (ADT) is a kind of composite type, i.e., a type formed by combining other types. Two common classes o
Const (computer programming)
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, const in the C famil
Object (computer science)
In computer science, an object can be a variable, a data structure, a function, or a method. As regions of memory, they contain value and are referenced by identifiers. In the object-oriented programm
String (computer science)
In computer programming, a string is traditionally a sequence of characters, either as a literal constant or as some kind of variable. The latter may allow its elements to be mutated and the length ch
Complex data type
Some programming languages provide a complex data type for complex number storage and arithmetic as a built-in (primitive) data type. In some programming environments the term complex data type (in co
First-class function
In computer science, a programming language is said to have first-class functions if it treats functions as first-class citizens. This means the language supports passing functions as arguments to oth
Raw data
Raw data, also known as primary data, are data (e.g., numbers, instrument readings, figures, etc.) collected from a source. In the context of examinations, the raw data might be described as a raw sco
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 a
Opaque data type
In computer science, an opaque data type is a data type whose concrete data structure is not defined in an interface. This enforces information hiding, since its values can only be manipulated by call
Variant type (COM)
Variant is a data type in certain programming languages, particularly Visual Basic, OCaml, Delphi and C++ when using the Component Object Model. It is an implementation of the eponymous concept in com
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
User-defined type
No description available.
Character (computing)
In computer and machine-based telecommunications terminology, a character is a unit of information that roughly corresponds to a grapheme, grapheme-like unit, or symbol, such as in an alphabet or syll
Latent typing
In computer programming, latent typing refers to a type system where types are associated with values and not variables. An example latently typed language is Scheme. This typically requires run-time
Indirection
In computer programming, indirection (also called dereferencing) is the ability to reference something using a name, reference, or container instead of the value itself. The most common form of indire
Advanced Scientific Data Format (ASDF) is a proposed replacement to the FITS standard for astronomical images and other scientific data. The metadata is contained in a YAML (Human-readable data serial
K-D-B-tree
In computer science, a K-D-B-tree (k-dimensional B-tree) is a tree data structure for subdividing a k-dimensional search space. The aim of the K-D-B-tree is to provide the search efficiency of a balan
List (abstract data type)
In computer science, a list or sequence is an abstract data type that represents a finite number of ordered values, where the same value may occur more than once. An instance of a list is a computer r
Anonymous function
In computer programming, an anonymous function (function literal, lambda abstraction, lambda function, lambda expression or block) is a function definition that is not bound to an identifier. Anonymou
Cons
In computer programming, cons (/ˈkɒnz/ or /ˈkɒns/) is a fundamental function in most dialects of the Lisp programming language. cons constructs memory o
Ordinal data type
In computer programming, an ordinal data type is a data type with the property that its values can be counted. That is, the values can be put in a one-to-one correspondence with the positive integers.
Value type and reference type
In computer programming, data types can be divided into two categories: value types (or by-value types) and reference types (or by-reference types). Value types are completely represented by their mea
Array (data type)
In computer science, array is a data type that represents a collection of elements (values or variables), each selected by one or more indices (identifying keys) that can be computed at run time durin
Option type
In programming languages (especially functional programming languages) and type theory, an option type or maybe type is a polymorphic type that represents encapsulation of an optional value; e.g., it
Opaque pointer
In computer programming, an opaque pointer is a special case of an opaque data type, a data type declared to be a pointer to a record or data structure of some unspecified type. Opaque pointers are pr
Variable-length quantity
A variable-length quantity (VLQ) is a universal code that uses an arbitrary number of binary octets (eight-bit bytes) to represent an arbitrarily large integer. A VLQ is essentially a base-128 represe
C data types
In the C programming language, data types constitute the semantics and characteristics of storage of data elements. They are expressed in the language syntax in form of declarations for memory locatio
Scalar (computing)
No description available.
Polymorphism (computer science)
In programming language theory and type theory, polymorphism is the provision of a single interface to entities of different types or the use of a single symbol to represent multiple different types.
Secondary data
Secondary data refers to data that is collected by someone other than the primary user. Common sources of secondary data for social science include censuses, information collected by government depart
Weak reference
In computer programming, a weak reference is a reference that does not protect the referenced object from collection by a garbage collector, unlike a strong reference. An object referenced only by wea
Interval arithmetic
Interval arithmetic (also known as interval mathematics, interval analysis, or interval computation) is a mathematical technique used to put bounds on rounding errors and measurement errors in mathema
Typing rule
In type theory, a typing rule is an inference rule that describes how a type system assigns a type to a syntactic construction. These rules may be applied by the type system to determine if a program
Type family
In computer science, a type family associates data types with other data types, using a type-level function defined by an open-ended collection of valid instances of input types and the corresponding
Reference (computer science)
In computer programming, a reference is a value that enables a program to indirectly access a particular data, such as a variable's value or a record, in the computer's memory or in some other storage
Word (computer architecture)
In computing, a word is the natural unit of data used by a particular processor design. A word is a fixed-sized datum handled as a unit by the instruction set or the hardware of the processor. The num
Catena (unit)
No description available.
Cardinal tree
A cardinal tree (or trie) of degree k, by analogy with cardinal numbers and by opposition with ordinal trees, is a rooted tree in which each node has k positions for an edge to a child. Each node has
Data type
In computer science and computer programming, a data type (or simply type) is a set of possible values and a set of allowed operations on it. A data type tells the compiler or interpreter how the prog
Void type
The void type, in several programming languages derived from C and Algol68, is the return type of a function that returns normally, but does not provide a result value to its caller. Usually such func
Product type
In programming languages and type theory, a product of types is another, compounded, type in a structure. The "operands" of the product are types, and the structure of a product type is determined by
Anonymous type
Anonymous types are a feature of C# 3.0, Visual Basic .NET 9.0, Oxygene, Scala and Go that allows data types to encapsulate a set of properties into a single object without having to first explicitly
Data file
A data file is a computer file which stores data to be used by a computer application or system, including input and output data. A data file usually does not contain instructions or code to be execut
Decimal32 floating-point format
In computing, decimal32 is a decimal floating-point computer numbering format that occupies 4 bytes (32 bits) in computer memory.It is intended for applications where it is necessary to emulate decima
Decimal64 floating-point format
In computing, decimal64 is a decimal floating-point computer numbering format that occupies 8 bytes (64 bits) in computer memory.It is intended for applications where it is necessary to emulate decima
Fixed-point arithmetic
In computing, fixed-point is a method of representing fractional (non-integer) numbers by storing a fixed number of digits of their fractional part. Dollar amounts, for example, are often stored with
Smart pointer
In computer science, a smart pointer is an abstract data type that simulates a pointer while providing added features, such as automatic memory management or bounds checking. Such features are intende
Null pointer
In computing, a null pointer or null reference is a value saved for indicating that the pointer or reference does not refer to a valid object. Programs routinely use null pointers to represent conditi
Tree (data structure)
In computer science, a tree is a widely used abstract data type that represents a hierarchical tree structure with a set of connected nodes. Each node in the tree can be connected to many children (de
Bounded pointer
In computer science, a bounded pointer is a pointer that is augmented with additional information that enable the storage bounds within which it may point to be deduced. This additional information so