title: Extracting unique numbers from string in R
body: <p>I have a list of strings which contain random characters such as:</p>
  
  <pre><code>list=list()
  list[1] = "djud7+dg[a]hs667"
  list[2] = "7fd*hac11(5)"
  list[3] = "2tu,g7gka5"
  </code></pre>
  
  <p>I'd like to know which numbers are present at least once (<code>unique()</code>) in this list. The solution of my example is:</p>
  
  <p>solution:  <code>c(7,667,11,5,2)</code></p>
  
  <p>If someone has a method that does not consider 11 as "eleven" but as "one and one", it would also be useful. The solution in this condition would be:</p>
  
  <p>solution:   <code>c(7,6,1,5,2)</code></p>
  
  <p>(I found this post on a related subject: <a href="https://stackoverflow.com/questions/14543627/extracting-numbers-from-vectors-of-strings">Extracting numbers from vectors of strings</a>)</p>