specify a <code>.p</code>, the default test is <code>isTRUE()</code>.</p>
<div class="sourceCode" id="cb29"><pre class="sourceCode r"><code class="sourceCode r"><a class="sourceLine" id="cb29-1" title="1">a &lt;-<span class="st"> </span><span class="kw">is.na</span>(airquality<span class="op">$</span>Ozone)</a>
<a class="sourceLine" id="cb29-2" title="2"><span class="kw"><a href="reference/messagehandler.html">message_if_any</a></span>(a, <span class="dt">msg =</span> <span class="st">"NA found"</span>)</a>