Editing Record (computer science) (section)

{{Short description|Composite data type}}
{{More citations needed|date=September 2021}}
In [[computer science]], a '''record''' (also called a '''structure''',  '''[[struct (C programming language)|struct]]''', or '''[[compound data type]]''') is a composite [[data structure]] {{endash}} a collection of [[Field (computer science)|fields]], possibly of different [[data type]]s, typically fixed in number and sequence.<ref>{{cite book |last1=Felleisen |first1=Matthias |title=How To Design Programs |url=https://archive.org/details/howtodesignprogr00fell_231 |url-access=registration |date=2001 |publisher=MIT Press |isbn=978-0262062183 |pages=[https://archive.org/details/howtodesignprogr00fell_231/page/n528 53], 60 }}</ref>

For example, a date could be stored as a record containing a [[Number|numeric]] <var>year</var> field, a <var>month</var> field represented as a string, and a numeric <var>day-of-month</var> field. A circle record might contain a numeric <var>radius</var> and a <var>center</var> that is a <var>point</var> record containing <var>x</var> and <var>y</var> coordinates.

Notable applications include the [[programming language]] ''record type'' and for row-based storage, data organized as a sequence of records, such as a [[database table]], [[spreadsheet]] or [[comma-separated values]] (CSV) file. In general, a record type value is stored in [[main memory|memory]] and row-based storage is in [[mass storage]].

A ''record type'' is a [[data type]] that describes such values and variables. Most modern programming languages allow the programmer to define new record types. The definition includes specifying the data type of each field and an [[identifier]] (name or label) by which it can be accessed.  In [[type theory]], [[product type]]s (with no field names) are generally preferred due to their simplicity, but proper record types are studied in languages such as [[System F-sub]].  Since type-theoretical records may contain [[first-class function]]-typed fields in addition to data, they can express many features of [[object-oriented programming]].