title: how to add a character to a string in R
body: <p>I have something like this:</p>
  
  <pre><code>text &lt;- "abcdefg"
  </code></pre>
  
  <p>and I want something like this:</p>
  
  <pre><code>"abcde.fg"
  </code></pre>
  
  <p>how could I achieve this without assigning a new string to the vector <code>text</code> but instead changing the element of the vector itself? Finally, I would like to randomly insert the dot and actually not a dot but the character element of a vector.</p>