Editing C (programming language) (section)

=== Operators ===
{{Main|Operators in C and C++}}

C supports a rich set of [[Operator (computer programming)|operators]], which are symbols used within an [[Expression (computer science)|expression]] to specify the manipulations to be performed while evaluating that expression. C has operators for:
* [[arithmetic]]: [[Addition|<code>+</code>]], [[Subtraction|<code>-</code>]], [[Multiplication|<code>*</code>]], [[Division (mathematics)|<code>/</code>]], [[Modulo operation|<code>%</code>]]
* [[Assignment (computer science)|assignment]]: <code>=</code>
* [[augmented assignment]]: {{codes|+{{=}}|-{{=}}|*{{=}}|/{{=}}|%{{=}}|&{{=}}|{{!}}{{=}}|^{{=}}|&lt;&lt;{{=}}|&gt;&gt;{{=}}|d=,{{space}}}}
* [[bitwise logic]]: <code>~</code>, <code>&</code>, <code>|</code>, <code>^</code>
* [[bitwise shift]]s: <code>&lt;&lt;</code>, <code>&gt;&gt;</code>
* [[Boolean logic]]: <code>!</code>, <code>&&</code>, <code>||</code>
* [[?:|conditional evaluation]]: [[?:|<code>? :</code>]]
* equality testing: [[Equality (mathematics)|<code>==</code>]], [[Inequality (mathematics)|<code>!=</code>]]
* [[Subroutine|calling functions]]: <code>( )</code>
* [[Increment and decrement operators|increment and decrement]]: <code>++</code>, <code>--</code>
* [[Record (computer science)|member selection]]: <code>.</code>, <code>-></code>
* object size: <code>[[sizeof]]</code>
* type: <code>[[typeof]]</code>, <code>typeof_unqual</code> ''since C23''
* [[order relation]]s: <code>&lt;</code>, <code>&lt;=</code>, <code>&gt;</code>, <code>&gt;=</code>
* [[Pointer (computer programming)|reference and dereference]]: <code>&</code>, <code>*</code>, <code>[ ]</code>
* sequencing: [[Comma operator|<code>,</code>]]
* [[Order of operations#Programming languages|subexpression grouping]]: <code>( )</code>
* [[type conversion]]: <code>(''typename'')</code>

C uses the operator <code>=</code> (used in mathematics to express equality) to indicate assignment, following the precedent of [[Fortran]] and [[PL/I]], but unlike [[ALGOL]] and its derivatives. C uses the operator <code>==</code> to test for equality. The similarity between the operators for assignment and equality may result in the accidental use of one in place of the other, and in many cases the mistake does not produce an error message (although some compilers produce warnings). For example, the conditional expression <code>if (a == b + 1)</code> might mistakenly be written as <code>if (a = b + 1)</code>, which will be evaluated as <code>true</code> unless the value of <code>a</code> is <code>0</code> after the assignment.<ref name="AutoTX-8">{{cite web |url=http://www.cs.ucr.edu/~nxiao/cs10/errors.htm |title=10 Common Programming Mistakes in C++ |website=Cs.ucr.edu |access-date=June 26, 2009 |archive-date=October 21, 2008 |archive-url=https://web.archive.org/web/20081021080953/http://www.cs.ucr.edu/~nxiao/cs10/errors.htm |url-status=live }}</ref>

The C [[operator precedence]] is not always intuitive. For example, the operator <code>==</code> binds more tightly than (is executed prior to) the operators <code>&</code> (bitwise AND) and <code>|</code> (bitwise OR) in expressions such as <code>x & 1 == 0</code>, which must be written as <code>(x & 1) == 0</code> if that is the coder's intent.<ref name="AutoTX-9">{{cite book |title=C and the 8051 |edition=3rd |last1=Schultz |first1=Thomas |year=2004 |publisher=PageFree Publishing Inc. |location=Otsego, MI |isbn=978-1-58961-237-2 |page=20 |url={{GBurl|id=rI0c8kWbxooC|pg=PT47}} |access-date=February 10, 2012 }}</ref>