="#optionals-and-optional-pointers"><span class="header-section-number">6.4</span> Optionals and Optional Pointers</a>
  <ul class="collapse">
  <li><a href="#what-are-optionals" id="toc-what-are-optionals" class="nav-link" data-scroll-target="#what-are-optionals"><span class="header-section-number">6.4.1</span> What are optionals?</a></li>
  <li><a href="#optional-pointers" id="toc-optional-pointers" class="nav-link" data-scroll-target="#optional-pointers"><span class="header-section-number">6.4.2</span> O