In computing, a scalar variable

Variable (programming)

In computer programming, a variable is a symbolic name given to some known or unknown quantity or information, for the purpose of allowing the name to be used independently of the information it represents...

 or field

Field (computer science)

In computer science, data that has several parts can be divided into fields. Relational databases arrange data as sets of database records, also called rows. Each record consists of several fields; the fields of all records form the columns....

 is one that can hold only one value at a time; as opposed to composite variables like array

Array data type

In computer science, an array type is a data type that is meant to describe a collection of elements , each selected by one or more indices that can be computed at run time by the program. Such a collection is usually called an array variable, array value, or simply array...

, list, hash

Associative array

In computer science, an associative array is an abstract data type composed of a collection of pairs, such that each possible key appears at most once in the collection....

, record

Object composition

In computer science, object composition is a way to combine simple objects or data types into more complex ones...

, etc. In some contexts, a scalar value may be understood to be numeric. A scalar data type is the type of a scalar variable. For example, char, int, float, and double are the most common scalar data types in the C programming language.

The origin of the term "scalar" in computing dates back to the 1970-80s, in the phrase "scalar processor

Scalar processor

Scalar processors represent the simplest class of computer processors. A scalar processor processes one datum at a time . , a scalar processor is classified as a SISD processor .In a vector processor, by contrast, a single instruction operates simultaneously on multiple data items...

". The intent was to distinguish this from vector processing in computer processor design.