="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"n/a"</span>,<span class="st">"No"</span><span class="op">)</span><span class="op">)</span><span class="op">)</span>
<span class="co">#&gt;   ID values</span>
<span class="co">#&gt; 1  A   &lt;NA&gt;</span>
<span class="co">#&gt; 2  B   &lt;NA&gt;</span>
<span class="co">#&gt; 3  B    Yes</span>
<span class="co">#&gt; 4  A   &lt;NA&gt;</span></code></pre></div>
