title: How to convert array to comma separated string in Puppet 2.7
body: <p>I am using Puppet 2.7 and I need to convert an array to comma separated list.</p>
  
  <pre><code>$hosts_fqdn= ['host1','host2','host3']
  </code></pre>
  
  <p>And I need to convert it to desired result: <code>'host1,host2,host3'</code></p>
  
  <p>I guess that Puppet 3.2 offers lambda expression - <code>reduce</code>. But unfortunately that is not possible with 2.7.</p>