 <code>c(out_cols)</code> or simply <code>(out_cols)</code>. Wrapping the variable name with <code>(</code> is enough to differentiate between the two cases.</p></li>
<li><p>The <code>LHS := RHS</code> form allows us to operate on multiple columns. In the RHS, to compute the <code>max</code> on columns specified in <code>.SDcols</code>, we make use of the base function <code>lapply()</code> along with <code>.SD</code> in the same way as we have seen before in the <em>“Introduction to data.table”</em> vi