数组中的唯一条目

我有以下内容将前 10 个 URL 存储到会话中：

function curPageURL() {
 $pageURL = 'http';
 if ($_SERVER["HTTPS"] == "on") {$pageURL .= "s";}
 $pageURL .= "://";
 if ($_SERVER["SERVER_PORT"] != "80") {
  $pageURL .= $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];
 } else {
  $pageURL .= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];
 }
 return $pageURL;
}
//Insert Current URL in SESSION
       $CurrentPage = curPageURL();
       if(strpos($CurrentPage, '/products/'))
        {
        echo "<div class=\"title\">Recently viewed products</div>
<div id=\"recent\">";
       $_SESSION['pages'][] = $CurrentPage;
       if ( Count ( $_SESSION['pages'] ) > 10 )
        Array_Shift ( $_SESSION['pages'] );

如何确保只存储唯一的条目？

谢谢， 乙

if(!in_array($CurrentPage, $_SESSION['pages']) {
    $_SESSION['pages'][] = $CurrentPage;
}