center vertically in bootstrap 4 code example

Example 1: bootstrap center text vertically

<div class=”row”>
	<div class=”col-6 align-self-center”>
    	<div class=”card card-block”>
    		Center
        </div>
    </div>
</div>

Example 2: vertical align bootstrap

<div class="row h-100">   <div class="col-sm-12 my-auto">     <div class="card card-block w-25">Card</div>   </div></div>