Editing "Hello, World!" program (section)

=="History"==
[[File:Hello World Brian Kernighan 1974.jpg|thumb|"Hello, World!" program handwritten in the [[C (programming language)|C language]] and signed by [[Brian Kernighan]] (1978)]]

While several small test programs have existed since the development of programmable [[computer]]s, the tradition of using the phrase "Hello, World!" as a test message was influenced by an example program in the 1978 book ''[[The C Programming Language]]'',<ref>{{cite book |last1=Kernighan |first1=Brian W. |author1-link=Brian Kernighan |last2=Ritchie |first2=Dennis M. |author2-link=Dennis Ritchie |date=1978 |title=The C Programming Language |edition=1st |publisher=[[Prentice Hall]] |location=[[Englewood Cliffs, New Jersey]] |isbn=0-13-110163-3 |url-access=registration |url=https://archive.org/details/cprogramminglang00kern}}</ref> with likely earlier use in [[BCPL]]. The example program from the book prints {{samp|"hello, world"}}, and was inherited from a 1974 [[Bell Labs|Bell Laboratories]] internal memorandum by [[Brian Kernighan]], ''Programming in C: A Tutorial'':<ref name="ctut">{{cite web |url=https://www.bell-labs.com/usr/dmr/www/ctut.pdf |title=Programming in C: A Tutorial |last1=Kernighan |first1=Brian |author1-link=Brian Kernighan |year=1974 |publisher=Bell Labs |url-status=live |archive-url=https://web.archive.org/web/20220322215231/https://www.bell-labs.com/usr/dmr/www/ctut.pdf |archive-date=22 March 2022 |access-date=9 January 2019}}</ref>
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Editor's Note: We do not need to have an example for every programming language ever created. Wikipedia is an encyclopedia. Please refrain from adding examples just because we can. If you think a particular example adds something unique and valuable to the article, petition on the talk page, first. Thanks. (User: DragonHawk)

Addendum: there are large repositories of Hello, World! programs all over the net, in every conceivable language. No need exists to list them all here. In fact, there is now a very comprehensive Wikibooks link: if you want to add a version for your language, do so there (you'll likely find it already exists). HERE IS NOT THE PLACE. The C version (which is not even correct in modern C) is here because it is the first in a non-obscure language, and the B example because it is the first known. There is no reason to have many others here. ADD NO MORE!
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<!-- See https://www.bell-labs.com/usr/dmr/www/ctut.pdf for original. -->
<syntaxhighlight lang="c">
main( ) {
        printf("hello, world");
}
</syntaxhighlight>

In the above example, the {{samp|main( )}} [[subroutine|function]] defines where the program [[Entry point|should start executing]]. The function body consists of a single [[Statement (computer science)|statement]], a call to the {{samp|printf()}} function, which stands for "''print f''ormatted"; it outputs to the [[Console application|console]] whatever is passed to it as the [[Parameter (computer programming)|parameter]], in this case the [[String (computer science)|string]] {{samp|"hello, world"}}.

The C-language version was preceded by Kernighan's own 1972 ''A Tutorial Introduction to the Language [[B (programming language)|B]]'',<ref name="langb">{{cite book |last1=Johnson |first1=S. C. |last2=Kernighan |first2=B. W. |author2-link=Brian Kernighan |url=https://www.bell-labs.com/usr/dmr/www/bintro.html |title=The Programming Language B |publisher=Bell Labs |url-status=live |archive-url=https://web.archive.org/web/20150611114355/https://www.bell-labs.com/usr/dmr/www/bintro.html |archive-date=11 June 2015 |access-date=8 August 2024}}</ref> where the first known version of the program is found in an example used to illustrate external variables:
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<syntaxhighlight lang="text">
main( ) {
    extrn a, b, c;
    putchar(a); putchar(b); putchar(c); putchar('!*n');
}
 
a 'hell';
b 'o, w';
c 'orld';
</syntaxhighlight>

The program above prints ''{{samp|hello, world!}}'' on the terminal, including a [[newline]] character. The phrase is divided into multiple variables because in B a character constant is limited to four [[ASCII]] characters. The previous example in the tutorial printed ''{{samp|hi!}}'' on the terminal, and the phrase ''{{samp|hello, world!}}'' was introduced as a slightly longer greeting that required several character constants for its expression.

The [[Jargon File]] reports that "hello, world" instead originated in 1967 with the language [[BCPL]].<ref>{{cite web |url=http://www.catb.org/jargon/html/B/BCPL.html |title=BCPL |work=[[Jargon File]] |access-date=21 April 2013 |archive-date=3 April 2018 |archive-url=https://web.archive.org/web/20180403000549/http://www.catb.org/jargon/html/B/BCPL.html |url-status=live}}</ref> Outside computing, use of the exact phrase began over a decade prior; it was the [[catchphrase]] of New York radio disc jockey [[William B. Williams (DJ)|William B. Williams]] beginning in the 1950s.<ref name=nytobit>{{cite web |url=https://select.nytimes.com/search/restricted/article?res=F50714FF3E5B0C778CDDA10894DE484D81| title=William B. Williams, Radio Personality, Dies |work=The New York Times |date=4 August 1986}}</ref>