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<p>
Next: <a href="if.html" accesskey="n" rel="next">if</a>, Previous: <a href="and.html" accesskey="p" rel="prev">and</a>, Up: <a href="Data-and-Control-Flow-Dictionary.html" accesskey="u" rel="up">Data and Control Flow Dictionary</a> </p>
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<hr>
<span id="cond-_005bMacro_005d"></span><h4 class="subsection">5.3.42 cond [Macro]</h4>
<p><code>cond</code> <i>{!<i>clause</i>}*</i> ⇒ <i>{<i>result</i>}*</i>
</p>
<p><i>clause</i> ::=<span class="roman">(</span><span class="nolinebreak">test-form</span> {<i>form</i>}*<span class="roman">)</span><!-- /@w -->
</p>
<span id="Arguments-and-Values_003a_003a-61"></span><h4 class="subsubheading">Arguments and Values::</h4>
<p><i>test-form</i>—a <i>form</i>.
</p>
<p><i>forms</i>—an <i>implicit progn</i>.
</p>
<p><i>results</i>—the <i>values</i> of the <i>forms</i>
in the first <i>clause</i> whose <i>test-form</i> <i>yields</i> <i>true</i>,
or the <i>primary value</i> of the <i>test-form</i>
if there are no <i>forms</i> in that <i>clause</i>,
or else <b>nil</b> if no <i>test-form</i> <i>yields</i> <i>true</i>.
</p>
<span id="Description_003a_003a-95"></span><h4 class="subsubheading">Description::</h4>
<p><b>cond</b> allows the execution of <i>forms</i> to be dependent
on <i>test-form</i>.
</p>
<p><i>Test-forms</i> are evaluated one at a time in the order in which
they are given in the argument list until a <i>test-form</i> is found that
evaluates to <i>true</i>.
</p>
<p>If there are no <i>forms</i> in that clause, the <i>primary value</i>
of the <i>test-form</i> is returned by the <b>cond</b> <i>form</i>.
Otherwise, the <i>forms</i> associated with this <i>test-form</i> are
evaluated in order, left to right, as an <i>implicit progn</i>, and the
<i>values</i> returned by the last <i>form</i>
are returned by the <b>cond</b> <i>form</i>.
</p>
<p>Once one <i>test-form</i> has <i>yielded</i> <i>true</i>,
no additional <i>test-forms</i> are <i>evaluated</i>.
If no <i>test-form</i> <i>yields</i> <i>true</i>, <b>nil</b> is returned.
</p>
<span id="Examples_003a_003a-69"></span><h4 class="subsubheading">Examples::</h4>
<div class="example">
<pre class="example"> (defun select-options ()
(cond ((= a 1) (setq a 2))
((= a 2) (setq a 3))
((and (= a 3) (floor a 2)))
(t (floor a 3)))) ⇒ SELECT-OPTIONS
(setq a 1) ⇒ 1
(select-options) ⇒ 2
a ⇒ 2
(select-options) ⇒ 3
a ⇒ 3
(select-options) ⇒ 1
(setq a 5) ⇒ 5
(select-options) ⇒ 1, 2
</pre></div>
<span id="See-Also_003a_003a-79"></span><h4 class="subsubheading">See Also::</h4>
<p><a href="if.html">if</a>
,
<a href="case.html">case</a>
.
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