title: saving lapply results to the list over which function applied
body: <p>In the spirit of "no question is too simple" , how do I save the output of an <code>lapply</code> function to the list on which it was applied. For e.g. I am doing </p>
  
  <p><code>lapply(listofdf, function(x) as.numeric(gsub("[$,]", "", x[ ,18])))</code></p>
  
  <p>where x is data frame and <code>gsub</code> is applied to 18th column. I want to save the result to the 18th column in the listofdf itself. I've never worked with lists. with a data frame we would simply do 
  <code>df$whatever &lt;- function(df$whatever, .... )</code> . With a <code>list</code> how would this work? </p>