Editing Indentation style (section)

=== K&R ===

The Kernighan & Ritchie (K&R) style is commonly used for C and C++ code and is the basis for many derivative styles. It is used in the original Unix kernel, [[Brian Kernighan|Kernighan]] and [[Dennis Ritchie|Ritchie]]'s book ''[[The C Programming Language]]'', as well as Kernighan and [[P. J. Plauger|Plauger]]'s book ''[[The Elements of Programming Style]]''.

Although ''[[The C Programming Language]]'' does not explicitly define this style, it follows it consistently. From the book:
<blockquote>
The position of braces is less important, although people hold passionate beliefs. We have chosen one of several popular styles. Pick a style that suits you, then use it consistently.
</blockquote>

In this style, a function has its opening and closing braces on their own lines and with the same indentation as the declaration, while the statements in the body of the function are indented an additional level. A multi-statement block inside a function, however, has its opening brace on the same line as its control clause while the closing brace remains on its own line unless followed by a keyword such as <code>else</code> or <code>while</code>.

Example code:

<syntaxhighlight lang="c">
int main(int argc, char *argv[])
{
    while (x == y) {
        do_something();
        do_something_else();
        if (some_error)
            fix_issue(); // single-statement block without braces
        else
            continue_as_usual();
    }
    final_thing();
}
</syntaxhighlight>

==== Egyptian braces ====

{{anchor|Egyptian}}
The non-[[typographic alignment|aligned]] braces of the multi-line blocks are nicknamed "Egyptian braces" (or "Egyptian brackets") for their resemblance to arms in some fanciful poses of ancient Egyptians.<ref>{{cite web |title=Java Style Guide |url=https://www.seas.upenn.edu/~cis120/current/java_style.shtml#f |quote=Using either "Egyptian" curly braces or C-style curly braces is acceptable |url-status=dead |archive-url=https://web.archive.org/web/20180712222126/https://www.seas.upenn.edu/~cis120/current/java_style.shtml |archive-date=2018-07-12}}</ref><ref>{{cite web |title=Egyptian brackets |url=http://foldoc.org/Egyptian+brackets |website=[[Foldoc]] |quote=A {{sic|humou|rous}} term for K&R indent style, referring to the "one hand up in front, one down behind" pose}}</ref><ref>{{cite web |title=Google JavaScript Style Guide |url=https://google.github.io/styleguide/jsguide.html#formatting-nonempty-blocks |quote=Braces follow the Kernighan and Ritchie style ("Egyptian brackets") for nonempty blocks and block-like constructs}}</ref>

==== Single statements ====

A single-statement block does not have braces, which is a cause of easy-to-miss bugs such as the [[Unreachable code#goto fail bug|goto fail bug]].