title: Combine an array to string in PHP
body: <p>I have a below array in PHP</p>
  
  <pre><code>$arrOrders['remains'] = 'ASC';
  $arrOrders['rate']    = 'DESC';
  </code></pre>
  
  <p>How can I use combine to a string like just with native function?</p>
  
  <pre><code>$str = 'remain ASC, rate DESC';
  </code></pre>