How to concatenate array of integers into comma separated string
<p>I have two question, acually:</p>

<ol>
<li>How to join array of integers into comma separated string? 
<em>(1,2,3) => "1,2,3"</em></li>
<li>How to convert array of integers to array of string? <em>(1,2,3) => ("1", "2", "3")</em></li>
</ol>



<pre><code>$arraylist = New-Object 'system.collections.arraylist'
$arraylist.Add(1);
$arraylist.Add(2);

$csv = ?? 
#($arraylist-join -',') returns error: Cannot convert value "," to type "System.Int32". Error: "Input string was not in a correct format."
</code></pre>