n class="k">TRUE</span><span class="p">)</span>
<span class="nv">$bar</span> <span class="o">=</span> <span class="k">FALSE</span><span class="p">;</span>
<span class="k">function</span> <span class="nf">foo</span><span class="p">(</span><span class="nv">$bar</span> <span class="o">=</span> <span class="k">NULL</span><span class="p">)</span>
</pre></div>
</div>
</div>
<div class="section" id="logical-operators">
<h2><a class="toc-backref" href="#id12">Logical Operators</a><a class="headerlink" href="#logica