title: Reduce array to a single string
body: <p>I would like to use the <code>reduce</code> function instead of doing this:</p>
  
  <pre><code>var result = '';
  authors.forEach(
      function(author) {
          result += author.name + ', ';
      }
  );
  console.log(result);
  </code></pre>
  
  <p>So in the array <code>authors</code> there are several names. Now I want to build a string with this names, separated by comma (except the last one).</p>
  
  <pre><code>var result = authors.reduce(function (author, index) {
      return author + ' ';
  }, '');
  console.log(result);
  </code></pre>