title: function which takes 3 argument
body: <p>I would like to have a function which takes 3 arguments:
  sentence (string), 
  maxCharLen=20 (number), 
  separator (string)</p>
  
  <p>Here is my example:
  Should it be possible to improve this code?</p>
  
  <pre><code>function breakSentence(sentence) {
     var newstring,
         maxCharLen = 20,
         separator = ',';
     for(var i=0; i &lt; sentence.length; i++) {
        newstring += sentence.charAt(i);
        if ((i % maxCharLen) === 0) {
           newstring += separator;
        }
     }
  }
  </code></pre>