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In `F33f`_`[data hierarchy`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Data_hierarchy]`_`f, a `!field`! (`!data field`!) is a `F33f`_`[variable`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Variable_(computer_science)]`_`f in a `F33f`_`[record`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Record_(computer_science)]`_`f.`:cite-ref-pascal-p42-quoted-1-0[`F5bf`_`[1`#cite-note-pascal-p42-quoted-1]`_`f] A record, also known as a `F33f`_`[data structure`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Data_structure]`_`f, allows logically related data to be identified by a single name. Identifying related data as a single group is central to the construction of understandable `F33f`_`[computer programs`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Computer_program]`_`f.`:cite-ref-cpl-p169-quote1-2-0[`F5bf`_`[2`#cite-note-cpl-p169-quote1-2]`_`f] The individual fields in a record may be accessed by name, just like any variable in a computer program.`:cite-ref-cpl-p169-3-0[`F5bf`_`[3`#cite-note-cpl-p169-3]`_`f]

Each field in a record has two components. One component is the field's `F33f`_`[datatype`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Data_type]`_`f `F33f`_`[declaration`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Declaration_(computer_programming)]`_`f. The other component is the field's `F33f`_`[identifier`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Identifier]`_`f.`:cite-ref-pascal-p42-4-0[`F5bf`_`[4`#cite-note-pascal-p42-4]`_`f]

>>Contents

• `F0af`_`[Memory fields`#memory-fields]`_`f

• `F0af`_`[File fields`#file-fields]`_`f

• `F0af`_`[See also`#see-also]`_`f

• `F0af`_`[References`#references]`_`f

-─

>>Memory fields

Fields may be stored in `F33f`_`[random access memory`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Random_access_memory]`_`f (RAM). The following `F33f`_`[Pascal`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Pascal_(programming_language)]`_`f record definition has three field identifiers: firstName, lastName, and age. The two name fields have a datatype of an `F33f`_`[array`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Array_(data_structure)]`_`f of `F33f`_`[character`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Character_(computing)]`_`f. The age field has a datatype of `F33f`_`[integer`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Integer]`_`f.

`B100`F9d9type PersonRecord =`f`b

`B100`F9d9 record`f`b

`B100`F9d9 lastName : array [ 1 .. 20 ] of Char;`f`b

`B100`F9d9 firstName : array [ 1 .. 20 ] of Char;`f`b

`B100`F9d9 age : Integer`f`b

`B100`F9d9 end;`f`b

In Pascal, the identifier component precedes a colon, and the datatype component follows the colon. Once a record is defined, `F33f`_`[variables`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Instance_variable]`_`f of the record can be `F33f`_`[allocated`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Instance_(computer_science)]`_`f. Once the memory of the record is allocated, a field can be accessed like a variable by using the dot notation.

`B100`F9d9var alice : PersonRecord;`f`b

`B100`F9d9alice.firstName := 'Alice';`f`b

The term `*field`* has been replaced with the terms `*data member`*`:cite-ref-stroustrup-p450-5-0[`F5bf`_`[5`#cite-note-stroustrup-p450-5]`_`f] and `*attribute`*.`:cite-ref-cpl-p104-6-0[`F5bf`_`[6`#cite-note-cpl-p104-6]`_`f] The following `F33f`_`[Java`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Java_(programming_language)]`_`f `F33f`_`[class`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Class_(computer_programming)]`_`f has three attributes: firstName, lastName, and age.

`B100`F9d9public class PersonRecord`f`b

`B100`F9d9{`f`b

`B100`F9d9 private String firstName;`f`b

`B100`F9d9 private String lastName;`f`b

`B100`F9d9 private int age;`f`b

`B100`F9d9}`f`b

>>File fields

Fields may be stored in a `F33f`_`[random access`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Random_access]`_`f `F33f`_`[file`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Computer_file]`_`f.`:cite-ref-cpl-p169-quote2-7-0[`F5bf`_`[7`#cite-note-cpl-p169-quote2-7]`_`f] A file may be written to or read from in an arbitrary order. To accomplish the arbitrary access, the `F33f`_`[operating system`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Operating_system]`_`f provides a method to quickly `*seek`* around the file.`:cite-ref-upe-p207-quote-8-0[`F5bf`_`[8`#cite-note-upe-p207-quote-8]`_`f] Once the `F33f`_`[disk head`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Disk_read-and-write_head]`_`f is positioned at the beginning of a record, each file field can be read into its corresponding memory field.

File fields are the main storage structure in the `F33f`_`[Indexed Sequential Access Method`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ISAM]`_`f (ISAM). In `F33f`_`[relational database`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Relational_database]`_`f `F33f`_`[theory`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Database_theory]`_`f, the term `*field`* has been replaced with the terms `*column`* and `*attribute`*.`:cite-ref-did-p5-quote-9-0[`F5bf`_`[9`#cite-note-did-p5-quote-9]`_`f]

>>See also

• `F33f`_`[Class variable`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Class_variable]`_`f – Variable defined in a class whose objects all possess the same copy

• `F33f`_`[Mutator method`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=Mutator_method]`_`f – Computer science method

>>References

`:cite-note-pascal-p42-quoted-1`!1.`! `F0af`_`[↑`#cite-ref-pascal-p42-quoted-1-0]`_`f `:citerefjensenwirth1974`aJensen, Kathleen; Wirth, Niklaus (1974). `*PASCAL User Manual and Report`*. Springer-Verlag. p. 42. `F33f`_`[ISBN`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ISBN_(identifier)]`_`f 0-387-90144-2. [A] record is a structure consisting of a fixed number of components, called fields.

`:cite-note-cpl-p169-quote1-2`!2.`! `F0af`_`[↑`#cite-ref-cpl-p169-quote1-2-0]`_`f `:citerefwilsonclark2001`aWilson, Leslie B.; Clark, Robert G. (2001). `*Comparative Programming Languages, Third Edition`*. Addison-Wesley. p. 169. `F33f`_`[ISBN`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ISBN_(identifier)]`_`f 0-201-71012-9. Being able to structure data in this way is central to the construction of understandable programs.

`:cite-note-cpl-p169-3`!3.`! `F0af`_`[↑`#cite-ref-cpl-p169-3-0]`_`f `:citerefwilsonclark2001`aWilson, Leslie B.; Clark, Robert G. (2001). `*Comparative Programming Languages, Third Edition`*. Addison-Wesley. p. 169. `F33f`_`[ISBN`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ISBN_(identifier)]`_`f 0-201-71012-9.

`:cite-note-pascal-p42-4`!4.`! `F0af`_`[↑`#cite-ref-pascal-p42-4-0]`_`f `:citerefjensenwirth1974`aJensen, Kathleen; Wirth, Niklaus (1974). `*PASCAL User Manual and Report`*. Springer-Verlag. p. 42. `F33f`_`[ISBN`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ISBN_(identifier)]`_`f 0-387-90144-2.

`:cite-note-stroustrup-p450-5`!5.`! `F0af`_`[↑`#cite-ref-stroustrup-p450-5-0]`_`f `:citerefstroustrup2013`aStroustrup, Bjarne (2013). `*The C++ Programming Language, Fourth Edition`*. Addison-Wesley. p. 450. `F33f`_`[ISBN`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ISBN_(identifier)]`_`f 978-0-321-56384-2.

`:cite-note-cpl-p104-6`!6.`! `F0af`_`[↑`#cite-ref-cpl-p104-6-0]`_`f `:citerefwilsonclark2001`aWilson, Leslie B.; Clark, Robert G. (2001). `*Comparative Programming Languages, Third Edition`*. Addison-Wesley. p. 104. `F33f`_`[ISBN`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ISBN_(identifier)]`_`f 0-201-71012-9.

`:cite-note-cpl-p169-quote2-7`!7.`! `F0af`_`[↑`#cite-ref-cpl-p169-quote2-7-0]`_`f `:citerefwilsonclark2001`aWilson, Leslie B.; Clark, Robert G. (2001). `*Comparative Programming Languages, Third Edition`*. Addison-Wesley. p. 169. `F33f`_`[ISBN`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ISBN_(identifier)]`_`f 0-201-71012-9. The original use of records was in languages like COBOL, where they were used to define the structure of records held in a file.

`:cite-note-upe-p207-quote-8`!8.`! `F0af`_`[↑`#cite-ref-upe-p207-quote-8-0]`_`f `:citerefkernighanpike1984`aKernighan, Brian W.; Pike, Rob (1984). `*The UNIX Programming Environment`*. Prentice Hall. p. 207. `F33f`_`[ISBN`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ISBN_(identifier)]`_`f 0-13-937699-2. The system call lseek provides a way to move around in a file without actually reading or writing.

`:cite-note-did-p5-quote-9`!9.`! `F0af`_`[↑`#cite-ref-did-p5-quote-9-0]`_`f `:citerefdate2005`aDate, C.J. (2005). `*Database in Depth`*. O'Reilly Media, Inc. p. 5. `F33f`_`[ISBN`:/page/wikibook/entry.mu`zim=wikipedia_en_all_nopic_2025-08.zim|entry_path=ISBN_(identifier)]`_`f 0-596-10012-4. An n-ary relation can be pictured as a table with n columns; the columns in the picture correspond to attributes of the relation and the rows correspond to tuples.

`c`F0af`_`[↑ Back to top`#top]`_`f`a