Program Variable

A Program Variable is a named data item (with a program variable name) within a software program.

• Context:
  • It can range from being an Untyped Program Variable to being a Typed Program Variable (with a Program Variable Type).
  • It can range from being a Mutable Variable to being an Immutable Variable.
• Example(s):
  • a Character String Variable, an Integer Variable, an Array Variable.
  • a Scala Variable, a Java Variable, a Perl Variable, a Python Variable, Scala Variable.
  • …
• Counter-Example(s):
  • a Data Structure.
  • a Program Control Structure.
  • a Persistent Data Record.
• See: Programming Language, Variable.

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References

2013

• http://www.tutorialspoint.com/python/python_variable_types.htm
  • Variables are nothing but reserved memory locations to store values. This means that when you create a variable you reserve some space in memory.

2009

• http://en.wikipedia.org/wiki/Variable_%28programming%29
  • QUOTE: In computer programming, a variable is an identifier (usually a letter, word, or phrase) that is linked to a value stored in the system's memory or an expression that can be evaluated. For instance, a variable might be called "total_count" and contain a number.

    In imperative programming languages, values can generally be accessed or changed at any time. However, in pure functional and logic languages, variables are bound to expressions and keep a single value during their entire lifetime due to the requirements of referential transparency. In imperative languages, the same behavior is exhibited by constants, which are typically contrasted with normal variables.

    Depending on the type system of a programming language, variables may only be able to store a specified datatype (e.g. integer or string). Alternatively a datatype may be associated only with the current value, allowing a single variable to store anything supported by the programming language.

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