reference/C/CONCEPT/expressions.html


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<head>
<title>C operators</title>
</head>
<body bgcolor="#ffffcc">
<hr>
<center>
<h1>C Operators/Expressions</h1>
</center>
<hr>
<p>

Operators are used with 
<a href="../glossary.html#operand">operands</a>
to build expressions. For example the 
following is an expression containing two operands and one oprator.

<pre>
        4 + 5
</pre>

The following list of operators is probably not complete but does highlight 
the common
operators and a few of the outrageous ones....
<p>
C contains the following operator groups.
<ul>
<li><a href="#arith">Arithmetic</a>
<li><a href="#ass">Assignment</a>
<li><a href="#rel">Logical/relational</a>
<li><a href="#bit">Bitwise</a>
<li><a href="#star">Odds and ends!</a>
<p>
<li><a href="precedence.html">Operator precedence table.</a>
</ul>
The order (precedence) that operators are evaluated can be seen 
<a href="precedence.html">here.</a>

<h2><a name=arith>Arithmetic</h2>
<pre>
        +
        -
        /
        *
        %       <a href="../EXAMPLES/modulo.c">modulo</a>
        --      <a href="inc_dec.html">Decrement</a> (post and pre)
        ++      <a href="inc_dec.html">Increment</a> (post and pre)
</pre>
<h2><a name=ass>Assignment</h2>
These all perform an arithmetic operation on the lvalue and assign the 
result to the lvalue. So what does this mean in English? Here is an example:
<pre>   counter = counter + 1; </pre>
can be reduced to 
<pre>   counter += 1;           </pre>
Here is the full set.
<pre>
        =
        *=      <a href="assignment.html">Multiply</a>
        /=      <a href="assignment.html">Divide.</a>
        %=      <a href="assignment.html">Modulus.</a>
        +=      <a href="assignment.html">add.</a>
        -=      <a href="assignment.html">Subtract.</a>
        <<=     <a href="assignment.html">left shift.</a>
        >>=     <a href="assignment.html">Right shift.</a>
        &=      <a href="assignment.html">Bitwise AND.</a>
        ^=      <a href="assignment.html">bitwise exclusive OR (XOR).</a>
        |=      <a href="assignment.html">bitwise inclusive OR.</a>
</pre>
<h2><a name=rel>Logical/Relational</h2>
<pre>
        ==      Equal to
        !=      Not equal to
        >
        <
        >=
        <=
        &&      <a href="../SYNTAX/logical.html">Logical AND</a>
        ||      <a href="../SYNTAX/logical.html">Logical OR</a>
        !       <a href="../SYNTAX/logical.html">Logical NOT</a>
</pre>
<h2><a name=bit>Bitwise</h2>
<pre>
        &       <a href="../CONCEPT/bitwise.html">AND (Binary operator)</a>
        |       <a href="../CONCEPT/bitwise.html">inclusive OR</a>
        ^       <a href="../CONCEPT/bitwise.html">exclusive OR</a>
        <<      <a href="../CONCEPT/bit_shift.html">shift left</a>. <font color=brown>C ++ use of <a href=../../CPLUSPLUS/SYNTAX/ops.html>&lt;&lt;</a></font>

        >>      <a href="../CONCEPT/bit_shift.html">shift right</a>. <font color=brown>C ++ use of <a href=../../CPLUSPLUS/SYNTAX/ops.html>&gt;&gt;</a></font>
        ~       <a href="../CONCEPT/bitwise.html">one's complement</a>
</pre>
<a name=comma>
<h2><a name=star>Odds and ends!</h2>
<pre>
        sizeof() <a href="../SYNTAX/sizeof.html">size</a> of objects and <a href="data_types.html">data types</a>.
                 <a href="../FUNCTIONS/strlen.html">strlen</a> may also be of interest.
        &       <a href="../EXAMPLES/address.c">Address of</a> (Unary operator)
        *       <a href="../EXAMPLES/address.c">pointer</a> (Unary operator)
        ?       <a href="../SYNTAX/conditional.html">Conditional expressions</a>
        :       <a href="../SYNTAX/conditional.html">Conditional expressions</a>
        ,       <a href="../SYNTAX/comma.html">Series operator.</a>
</pre>
<hr>
<p>
<h2>C++ Extensions</h2>

<font color=brown>
Read about :: &gt;&gt; and &lt;&lt; in the world of C++
<a href=../../CPLUSPLUS/SYNTAX/ops.html>here!</a>
</font>
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<address>Martin Leslie
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