title: array_diff to compare two associative arrays
body: <p>I'm confusing array_diff behavior</p>
  <p>why genre don't exist on diff array?
  Do you know how to resolve the matter?</p>
  <p>-code</p>
  <pre><code>&lt;?php
  $array1 = array
  (
      'value01' =&gt; '0',
      'value02' =&gt; 'v2',
      'genre' =&gt; '1',
      'type' =&gt; 'text',
      'contry' =&gt; 'us',
      'data' =&gt; '1',
  );
  $array2 = array
  (
      'value01' =&gt; 'v1',
      'value02' =&gt; 'v2',
      'genre' =&gt; '0',
      'type' =&gt; 'text',
      'contry' =&gt; 'canada',
      'data' =&gt; '1',
  );
  
  print_r(array_diff($array1,$array2));
  </code></pre>
  <p>My result:</p>
  <pre><code>Array
  (
      [contry] =&gt; us
  )
  </code></pre>
  <p>But I expect:</p>
  <pre><code>Array
  (
      [value01] =&gt; 0,
      [genre] =&gt; 1,
      [contry] =&gt; us,
  );
  </code></pre>