{{Short description|Placeholder variables in programming}} {{Distinguish|FUBAR|foobar2000|FUBAR (TV series)}} {{Redirect|Foo|other uses|Foo (disambiguation)|the acronym|FOO}} [[File:TC-dbl.PNG|thumb|231x231px|Foobar being used to show transclusion]] {{Use dmy dates|date=February 2020|cs1-dates=y}} The terms '''''foobar''''',{{efn|{{IPAc-en|ˈ|f|uː|b|ɑr}}}} '''''foo''''', '''''bar''''', '''''baz''''', '''''quux''''',{{efn|{{IPAc-en|k|w|V|k|s}}, regardless of length.<ref>{{cite web |title=quux |url=http://www.catb.org/jargon/html/Q/quux.html |access-date=9 September 2025 |archive-url=https://web.archive.org/web/20250427135345/https://www.catb.org/jargon/html/Q/quux.html |archive-date=2025-04-27 |language=en |quote=quux: {{nowrap|/kwuhks/}} |url-status=live |editor-last=Eric S. Raymond |version=4.4.7 |website=Jargon File}}</ref> Can be extended as '''''quu(u…)x''''' for ''n'' desired variables; this includes the (more modern) backwards extrapolation '''''qux'''''.<ref>{{cite web |title=qux |url=http://www.catb.org/jargon/html/Q/qux.html |access-date=9 September 2025 |archive-url=https://web.archive.org/web/20250428021800/https://www.catb.org/jargon/html/Q/qux.html |archive-date=2025-04-28 |language=en |quote=qux: {{nowrap|/kwuhks/}} […] the quu(u...)x series |url-status=live |editor-last=Eric S. Raymond |version=4.4.7 |website=Jargon File}}</ref>}} and others are used as metasyntactic variables in computer programming or computer-related documentation.<ref>{{Cite web |editor-last=Eric S. Raymond |version=4.4.8 |title=metasyntactic variable |url=http://www.catb.org/jargon/html/M/metasyntactic-variable.html |access-date=2024-05-30 |website=Jargon File}}</ref><ref name="rfc3092">{{IETF RFC|3092}} - Etymology of "Foo"</ref> They have been used to name entities such as variables, functions, and commands whose exact identity is unimportant and serve only to demonstrate a concept.
== History and etymology == {{wiktionary|foobar|foo|bar|baz|quux|qux}} It is possible that ''foobar'' is a playful allusion to the World War II-era military slang FUBAR (''fucked up beyond all recognition)''.<ref name="dictionary">{{Cite web|url=https://www.dictionary.com/e/foo/|title=What does foo mean?|publisher=Dictionary.com|access-date=2019-08-17}}</ref>
According to an RFC from the Internet Engineering Task Force, the word ''FOO'' originated as a nonsense word with its earliest documented use in the 1930s comic ''Smokey Stover'' by Bill Holman.<ref name="rfc30922">{{cite web|last1=Eastlake|first1=D|last2=Manros|first2=C|last3=Raymond|first3=E|title=Etymology of "Foo"|url=http://www.ietf.org/rfc/rfc3092.txt|website=The Internet Engineering Task Force|accessdate=17 April 2016}}</ref> Holman states that he used the word due to having seen it on the bottom of a jade Chinese figurine in San Francisco Chinatown, purportedly signifying "good luck".<ref>{{Cite web|url=https://www.smokey-stover.com/history.html|title=The History of Bill Holman|date=2007-06-13|publisher=Smokey Stover|access-date=2019-08-17}}</ref> If true, this is presumably related to the Chinese word ''fu'' ("{{lang|zh|福}}", sometimes transliterated ''foo'', as in ''foo dog''), which can mean ''happiness'' or ''blessing''.<ref>Mieke Matthyssen, "Chinese happiness: A proverbial approach to popular philosophies of life", p. 190, ch. 9 in, Gerda Wielander, Derek Hird (eds), ''Chinese Discourses on Happiness'', Hong Kong University Press, 2018 {{ISBN|9888455729}}.</ref>
The first known use of the terms in print in a programming context appears in a 1965 edition of MIT's ''Tech Engineering News''.<ref>{{cite book|url=https://books.google.com/books?id=aOQRAQAAMAAJ&q=foobar|title=Tech Engineering News|volume=47|year=1965|publisher=Massachusetts Institute of Technology|page=63|quote=Further, it is possible to search for an effective address; e.g., if an instruction such as "add 1 foo" were used, specifying indirect addressing thru location "foo", and location "foo" contained the address of location "foobar", then an effective word search for "foobar" would find location "foo" and the location containing the "add" instruction as well.}}</ref> The use of ''foo'' in a programming context is generally credited to the Tech Model Railroad Club (TMRC) of MIT from {{circa|1960}}.<ref name="rfc3092" /> In the complex model system, there were scram switches located at multiple places around the room that could be thrown if something undesirable was about to occur, such as a train moving at full power towards an obstruction. Another feature of the system was a digital clock on the dispatch board. When someone hit a scram switch, the clock stopped and the display was replaced with the word "FOO"; at TMRC the scram switches are, therefore, called "Foo switches". Because of this, an entry in the 1959 ''Dictionary of the TMRC Language'' stated: "FOO: The first syllable of the misquoted sacred chant phrase 'foo mane padme hum.' Our first obligation is to keep the foo counters turning."<ref>{{cite web|url=https://www.computer-dictionary-online.org/definitions-f/foo.html|title=Computer Dictionary Online}}, computer-dictionary-online.org</ref> One book{{which|date=November 2010}} describing the MIT train room describes two buttons by the door labeled "foo" and "bar". These were general-purpose buttons and were often repurposed for whatever fun idea the MIT hackers had at the time, hence the adoption of ''foo'' and ''bar'' as general-purpose variable names. An entry in the ''Abridged Dictionary of the TMRC Language'' states:<ref>{{cite web|url=http://tmrc.mit.edu/dictionary.html#FOO|title=Abridged Dictionary of the TMRC Language|publisher=Tech Model Railroad Club of MIT|access-date=2013-03-12|archive-url=https://web.archive.org/web/20180102215225/http://tmrc.mit.edu/dictionary.html#FOO|archive-date=2 January 2018|url-status=dead}}</ref>
{{Blockquote|text = Multiflush: stop-all-trains-button. Next thing to the red door button. Also called FOO. Displays "FOO" on the clock when used.}}
''Foobar'' was used as a variable name in the Fortran code of ''Colossal Cave Adventure'' (1977 Crowther and Woods version). The variable ''FOOBAR'' was used to contain the player's progress in saying the magic phrase "Fee Fie Foe Foo", a phrase from a historical quatrain in the classic English fairy tale Jack and the Beanstalk. Intel also used the term ''foo'' in their programming documentation in 1978.<ref name="Intel_1978_MSC86-OI"/>
==Examples in culture== * Foo Camp is an annual hacker convention. * BarCamp, an international network of user-generated conferences. * During the ''United States v. Microsoft Corp.'' trial, evidence was presented that Microsoft had tried to use the Web Services Interoperability organization (WS-I) as a means to stifle competition, including e-mails in which top executives including Bill Gates and Steve Ballmer referred to the WS-I using the codename "foo".<ref>{{cite web | url=https://www.cnet.com/news/microsoft-ploy-to-block-sun-exposed/ | title=Microsoft ploy to block Sun exposed | date=2002-07-04 | author=Mike Ricciuti | publisher=CNET | access-date=2019-08-17}}</ref> * foobar2000 is an audio player.
== See also == {{Portal|Computer programming}} * Alice and Bob * Foo fighter * Foo was here * Lorem ipsum, similar placeholder text used outside programming * xyzzy * :Category:Variable (computer science) {{Clear}}
== Notes == {{notelist}}
== References == {{Reflist|refs= <ref name="Intel_1978_MSC86-OI">{{cite book |title=MCS-86 Assembler Operating Instructions For ISIS-II Users |id=Manual Order No. 9800641A |date=1978 |edition=A32/379/10K/CP |publisher=Intel Corporation |location=Santa Clara, California, USA |url=https://archive.org/details/bitsavers_intelISISIblerOperatingInstructionsforISISIIUsersM_3593319/ |access-date=2020-02-29}} [https://archive.org/stream/bitsavers_intelISISIblerOperatingInstructionsforISISIIUsersM_3593319/9800641A_MCS-86_Assembler_Operating_Instructions_for_ISIS-II_Users_Mar79_djvu.txt][https://archive.org/download/bitsavers_intelISISIblerOperatingInstructionsforISISIIUsersM_3593319/9800641A_MCS-86_Assembler_Operating_Instructions_for_ISIS-II_Users_Mar79.pdf]</ref> }}
== External links == * [https://developers.google.com/style/word-list Google developer documentation style guide word list] * [http://www.catb.org/jargon/html/F/foo.html The Jargon File entry on "foobar"], catb.org * {{IETF RFC|1639}} – FTP Operation Over Big Address Records (FOOBAR)
Category:Placeholders Category:Computer programming folklore Category:Articles with example C code Category:Computing terminology