Smarty模板进行数据类型渲染输出

<?php
require __DIR__.'/config/config.php';
session_start();
class Test{
  public  $site='php中文网';
  public function welcome(){
      return'欢迎来到'.$this->site;
  }
}
function add($a,$b){
   return $a+$b;
}
$test=new Test();
//设置常量。不用赋值
const SITE_NAME='努力学习';
//系统常量
$_POST['username']='天天向上';
$_GET['username']='少儿不努力，老大徒伤悲';
$_SESSION['pass']=sha1('123456');
$smarty->assign('test',$test);
$smarty->display('demo6.html');