title: R count number of commas and string
body: <p>I have a string:</p>
  
  <pre><code>    str1 &lt;- "This is a string, that I've written 
          to ask about a question, or at least tried to."
  </code></pre>
  
  <p>How would I :</p>
  
  <p>1) count the number of commas</p>
  
  <p>2) count the occurences of '-ion'</p>
  
  <p>Any suggestions?</p>