title: How count elements in an column that are not empty
body: <p>I just started with R, and i have to count elements from an column that are not empty.
  For example : </p>
  
  <pre><code>   exampleColumn
  1 "heey"
  2
  3 "World"
  4 "how are you "
  </code></pre>
  
  <p>How can I achieve this ? </p>