|
Identifiers (IDs) are lexical tokens that name entities. The concept is analogous to that of a "name". Identifiers are used extensively in virtually all information processing systems. Naming entities makes it possible to refer to them, which is essential for any kind of processing. It has been suggested that this article or section be merged with Tokenizing. ...
An entity is something that has a distinct, separate existence, though it need not be a material existence. ...
Analogy is either the cognitive process of transferring information from a particular subject (the analogue or source) to another particular subject (the target), or a linguistic expression corresponding to such a process. ...
A name is a verbal label for a thing, person, place, product (as in a brand name) and even an idea or concept, normally used to distinguish one from another. ...
An information processor or information processing system, as its name suggests, is a system (be it electrical, mechanical or biological) which takes information (a sequence of enumerated states) in one form and processes (transforms) it into another form, e. ...
Identifiers in computer languages
In computer languages, identifiers are textual tokens (also called symbols) which name language entities. In programming languages, examples of such entities are variables, types, labels, subroutines, packages, etc. A computer language is a language used by, or in association with, computers. ...
It has been suggested that this article or section be merged with Tokenizing. ...
Other listings of programming languages are: Categorical list of programming languages Generational list of programming languages Chronological list of programming languages Note: Esoteric programming languages have been moved to the separate List of esoteric programming languages. ...
In computer science and mathematics, a variable (sometimes called a pronumeral) is a symbol denoting a quantity or symbolic representation. ...
In computer science, a datatype or data type (often simply a type) is a name or label for a set of values and some operations which one can perform on that set of values. ...
A label is any kind of tag attached with adhesive to something so as to identify the object or its contents. ...
In computer science, a subroutine (function, method, procedure, or subprogram) is a portion of code within a larger program, which performs a specific task and is relatively independent of the remaining code. ...
A software package is a special method for the distribution and installation of software on computer systems. ...
Computer languages usually place restrictions on what an identifier may look like. For example, in C++, one restriction is that identifiers must be composed of ASCII letters, digits, and underscores. Some modern languages allow unicode characters for identifiers, for non english speaking people. For a WikiBook on programming with C++, see Wikibooks: C++ Programming. ...
In compiled programming languages, identifiers are compile time entities. That is, at runtime the compiled program operates in terms of memory addresses and offsets, and the textual identifier tokens are no longer present or used. A compiler is a computer program that translates a computer program written in one computer language (called the source language) into an equivalent program written in another computer language (called the output or the target language). ...
In computer science, compile time, as opposed to runtime, is the time when a compiler compiles code written in a programming language into an executable form. ...
In computer science, run time (with a space, though often its spelled without one) describes the operation of a computer program, the duration of its execution, from beginning to termination (compare compile time). ...
In interpreted languages identifiers often are available at runtime, sometimes even as first-class objects which can be freely manipulated and evaluated. In computer programming, an interpreted language is a programming language whose programs may be executed from source form, by an interpreter. ...
In computing, a first-class object (also -value, -entity, -citizen), in the context of a particular programming language, is an entity which can be used in programs without restriction (when compared to other kinds of objects in the same language). ...
Compilers and interpreters usually do not attach meaning to the actual identifier chosen for an entity, as long as it is unique within a certain context. However, there are exceptions. For example:
- in Ruby a variable is automatically considered immutable if its identifier starts with a capital letter;
- in Fortran, the first letter in a variable's name indicates whether by default it is created as an integer or floating point variable.
Ruby is a reflective, object-oriented programming language. ...
In computer science, an immutable object, as opposed to a mutable object, is a kind of object whose internal states cannot be modified after it is created. ...
Fortran (also FORTRAN) is a general-purpose[1], procedural[2], imperative programming language that is especially suited to numeric computation and scientific computing. ...
The integers consist of the positive natural numbers (1, 2, 3, …), their negatives (−1, −2, −3, ...) and the number zero. ...
A floating-point number is a digital representation for a number in a certain subset of the rational numbers, and is often used to approximate an arbitrary real number on a computer. ...
See also |
Feeds |
Contact