title: How to save console result into an new column? in r
body: <p>I have a df with 38 columns and 405 rows.</p>
  <p>In the last 30 columns there are integer values saved. I want to sum them up into a new column.</p>
  <p>The console result is right but I don't know how to safe it into a new column in the same df.</p>
  <pre><code>df %&gt;% 
    replace(is.na(.), 0) %&gt;% 
     mutate(sum = rowSums(.[9:38])) 
  </code></pre>