how to vertically center a div in bootstrap code example

Example 1: bootstrap div vertical center

<div class="jumbotron d-flex align-items-center min-vh-100">
  <div class="container text-center">
    I am centered vertically
  </div>
</div>

Example 2: how to center vertically in bootstrap col

<div class="my-auto">
  ...inner divs and content...
</div>