title: Using array_diff(), how to get difference from array2 instead of array1?
body: <p>I'm trying to use array_diff like so.  Here are my two array outputs:</p>
  <p>List 1 Output</p>
  <pre><code>Array ([0] =&gt; 0022806 ) 
  </code></pre>
  <p>List 2 Output</p>
  <pre><code>Array ([0] =&gt; 0022806 [1] =&gt; 0023199 ) 
  </code></pre>
  <p>PHP</p>
  <pre><code>$diff = array_diff($list_1, $list_2);
  
  print &quot;DIFF: &quot; . count($diff) .&quot;&lt;br&gt;&quot;;
  print_r($diff);
  </code></pre>
  <p>The Output is:</p>
  <pre><code>DIFF: 0
  Array ( )
  </code></pre>
  <p>Any idea what I'm doing wrong?  Why is <code>0023199</code> not returned?</p>