title: Convert a for loop to concat String into a lambda expression
body: <p>I have the following for loop which iterates through a list of strings and stores the first character of each word in a <code>StringBuilder</code>.  I would like to know how can I transform this to a lambda expression</p>
  
  <pre><code>StringBuilder chars = new StringBuilder();
  for (String l : list) {
      chars.append(l.charAt(0));
  }  
  </code></pre>