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| 22 | <title>Simple Assignment (GNU C Language Manual)</title>
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| 31 | <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
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| 32 | <link href="Assignment-Expressions.html" rel="up" title="Assignment Expressions">
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| 57 | <body lang="en">
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| 58 | <span id="Simple-Assignment"></span><div class="header">
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| 59 | <p>
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| 60 | Next: <a href="Lvalues.html" accesskey="n" rel="next">Lvalues</a>, Up: <a href="Assignment-Expressions.html" accesskey="u" rel="up">Assignment Expressions</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Symbol-Index.html" title="Index" rel="index">Index</a>]</p>
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| 61 | </div>
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| 62 | <hr>
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| 63 | <span id="Simple-Assignment-1"></span><h3 class="section">7.1 Simple Assignment</h3>
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| 64 | <span id="index-simple-assignment"></span>
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| 65 | <span id="index-assignment_002c-simple"></span>
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| 66 |
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| 67 | <p>A <em>simple assignment expression</em> computes the value of the right
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| 68 | operand and stores it into the lvalue on the left. Here is a simple
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| 69 | assignment expression that stores 5 in <code>i</code>:
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| 70 | </p>
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| 71 | <div class="example">
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| 72 | <pre class="example">i = 5
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| 73 | </pre></div>
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| 74 |
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| 75 | <p>We say that this is an <em>assignment to</em> the variable <code>i</code> and
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| 76 | that it <em>assigns</em> <code>i</code> the value 5. It has no semicolon
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| 77 | because it is an expression (so it has a value). Adding a semicolon
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| 78 | at the end would make it a statement (see <a href="Expression-Statement.html">Expression Statement</a>).
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| 79 | </p>
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| 80 | <p>Here is another example of a simple assignment expression. Its
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| 81 | operands are not simple, but the kind of assignment done here is
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| 82 | simple assignment.
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| 83 | </p>
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| 84 | <div class="example">
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| 85 | <pre class="example">x[foo ()] = y + 6
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| 86 | </pre></div>
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| 87 |
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| 88 | <p>A simple assignment with two different numeric data types converts the
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| 89 | right operand value to the lvalue’s type, if possible. It can convert
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| 90 | any numeric type to any other numeric type.
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| 91 | </p>
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| 92 | <p>Simple assignment is also allowed on some non-numeric types: pointers
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| 93 | (see <a href="Pointers.html">Pointers</a>), structures (see <a href="Structure-Assignment.html">Structure Assignment</a>), and
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| 94 | unions (see <a href="Unions.html">Unions</a>).
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| 95 | </p>
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| 96 | <p><strong>Warning:</strong> Assignment is not allowed on arrays because
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| 97 | there are no array values in C; C variables can be arrays, but these
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| 98 | arrays cannot be manipulated as wholes. See <a href="Limitations-of-C-Arrays.html">Limitations of C Arrays</a>.
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| 99 | </p>
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| 100 | <p>See <a href="Assignment-Type-Conversions.html">Assignment Type Conversions</a>, for the complete rules about data
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| 101 | types used in assignments.
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| 102 | </p>
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| 103 |
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| 104 |
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| 105 |
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