求帮忙解释函数含义

public function upsave(){
$pat = "/<(\/?)(script|i?frame|style|html|body|title|font|strong|span|div|marquee|link|meta|\?|\%)([^>]*?)>/isU";
$_POST['info'] = preg_replace($pat,"",$_POST['info']);
$n_arr = explode(',', $_POST['classid']);
$_POST['classid'] = intval($n_arr[0]);
$_POST['classname'] = $n_arr[1];
     if($_FILES['upfile']['name']){
$img = $this->_upload();
$_POST['pic'] = $img[0]['savepath'].$img[0]['savename'];
     }
$this->all_save();
}
求解释这个函数的意思