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<html><head><title>XLISP get</title>
<link rel="stylesheet" type="text/css" href="reference.css">
</head>
<body>
<a href="../start.htm">Nyquist / XLISP 2.0</a> -
<a href="../manual/contents.htm">Contents</a> |
<a href="../tutorials/tutorials.htm">Tutorials</a> |
<a href="../examples/examples.htm">Examples</a> |
<a href="reference-index.htm">Reference</a>
<hr>
<h1>get</h1>
<hr>
<p><table cellpadding="0" cellspacing="0" style="margin-left:10px"><tbody>
<tr valign="top">
<td><nobr>Type:</nobr></td>
<td><nobr> - </nobr></td>
<td width="100%"><nobr>function (subr)</nobr></td>
</tr>
<tr valign="top">
<td><nobr>Source:</nobr></td>
<td><nobr> - </nobr></td>
<td width="100%"><nobr>xlbfun.c</nobr></td>
</tr>
</tbody></table></p>
<h2>Syntax</h2>
<dl>
<dt>(get <i>symbol property</i>)</dt>
<dd><i>symbol</i> - the symbol with a property list<br>
<i>property</i> - he property name being retrieved<br>
returns - the property value or <a href="nil.htm">NIL</a></dd>
</dl>
<h2>Description</h2>
<p>The 'get' function returns the value of the'property' from the 'symbol'.
If the 'property' does not exist, a <a href="nil.htm">NIL</a> is
returned. The 'symbol' must be an existing symbol. The returned value may be
a single value or a list.</p>
<p>Property lists are lists attached to any user defined variables. The
lists are in the form of:</p>
<pre class="example">
(<font color="#008844"><i>name1 value1 name2 value2</i></font> ... )
</pre>
<p>Any number of properties may be attached to a single variable.</p>
<h2>Examples</h2>
<pre class="example">
(setq person 'bobby) <font color="#008844">; create a variable with a value</font>
(putprop person 'boogie 'last-name) <font color="#008844">; add a LAST-NAME property</font>
(putprop person 'disc-jockey 'job) <font color="#008844">; add a JOB property</font>
(get person 'last-name) <font color="#008844">; retrieve LAST-NAME - boogie</font>
(get person 'job) <font color="#008844">; retrieve JOB - disc-jockey</font>
(get person 'height) <font color="#008844">; non-existant - returns NIL</font>
(putprop person '(10 20 30) 'stats) <font color="#008844">; add STATS - a list</font>
(get person 'stats) <font color="#008844">; retrieve STATS - (10 20 30)</font>
</pre>
<p><b>Note:</b> You can set a property to the value
<a href="nil.htm">NIL</a>. However, this
<a href="nil.htm">NIL</a> value is indistinguishable from the
<a href="nil.htm">NIL</a> returned when a property does not
exist.</p>
<p><b>Common Lisp:</b> Common Lisp allows for an optional default value,
which XLISP does not support.</p>
<p>See the
<a href="../manual/xlisp-man-014.htm#get">get</a>
function in the <nobr>XLISP 2.0</nobr> manual.</p>
<p><nobr> <a href="#top">Back to Top</nobr></a></p>
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