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<title>The UNION keyword.</title>
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<center><h1>The UNION keyword.</h1></center>
<hr>
The <b>union</b> <a href="../glossary.html#keyword">keyword</a> allows several
variables of different type and size to occupy the same storage location.
<p>
The syntax to define a union is simular to the
<a href="struct.html">struct</a> keyword as shown below:<p>
<pre>
union union_def { int a; float b; char c;} ;
</pre>
and a variable declared with either of these statements:
<pre>
union union_def union_var;
union { int a; float b; char c;} union_var;
</pre>
If you wish to initalise a variable you can say:
<pre>
union { int a; float b; char c;} union_var=97;
</pre>
By default the first variable (<b>a</b>) is initalised.
<p>
To assign a value to a variable you can say:
<pre>
union_var.b=99.99;
union_var.a=34;
union_var.c='x';
</pre>
It's important to note that the storage will only hold ONE value,
looking at the
three lines above, <b>union_var.a</b> overwrites <b>union_var.b</b> and
then <b>union_var.c</b> overwrites <b>union_var.a</b><p>
I have yet to see more than one use for this keyword.
<hr>
<h2>Examples:</h2>
<img src="../../GRAPHICS/computer.gif" align=left>
<a href="../EXAMPLES/union.c"> Here is an example.</a>
<br clear=left>
<hr>
<h2>See also:</h2>
<ul>
<li><a href="struct.html">struct</a> keyword.
</ul>
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<address>Martin Leslie
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