title: column bind in R and name the column
body: <p>I want to column bind (cbind) <code>mydf[,"c"]</code> and give it a new name <code>newcolumn</code> in one step and get the result matrix <code>mydf</code>. How do I do it?</p>
  
  <pre><code>mydf
  # a b c 
  # 1 2 6
  # 1 3 4
  
  
  mydf
  # a b c newcolumn
  # 1 2 6         6
  # 1 3 4         4
  </code></pre>