关于用户注册页面有几句不明白

Question

这段代码是用户注册页面进行提交，需要的PHP代码，
我想问一下这一段代码里面，以下的这两段有什么用呢？
 $obj=new save_reg($_POST["usernc"],md5($_POST["userpwd1"]),$_POST["truename"],$_POST["sex"],$_POST["email"],$_POST["tel"],$_POST["qq"],$_POST["photo"],$_POST["address"]);
 $obj->savereg();以下是全部代码的部分：
<?php
session_start(); class save_reg{
 
   private $usernc;
   private $userpwd;
   private $truename;
   private $sex;
   private $email;
   private $tel;
   private $qq;
   private $photo;
   private $address;
   
   public function __construct($usernc,$userpwd,$truename,$sex,$email,$tel,$qq,$photo,$address){
       $this->usernc=$usernc;
   $this->userpwd=$userpwd;
   $this->truename=$truename;
   $this->sex=$sex;
   $this->email=$email;
   $this->tel=$tel;
   $this->qq=$qq;
   $this->photo=$photo;
   $this->address=$address;
   }
   
   public function savereg(){
      include_once("conn.php");
 $sql=mysql_query("select usernc from tb_user where usernc='".$this->usernc."'",$conn);
        if($info=mysql_fetch_array($sql)){
     echo "<script>alert('该用户昵称已经被占用，请重新选择！');history.back();</script>";
 exit;
  }
  
      if(mysql_query("insert into tb_user(usernc,pwd,truename,email,sex,tel,qq,photo,address,logintimes,regtime,lastlogintime,ip) values('".$this->usernc."','".$this->userpwd."','".$this->truename."','".$this->email."','".$this->sex."','".$this->tel."','".$this->qq."','".$this->photo."','".$this->address."','1','".date("Y-m-j H:i:s")."','".date("Y-m-j H:i:s")."','".$_SERVER["PHP_SELF"]."')",$conn)){
    if($_SESSION["unc"]!=""){
   session_unregister("unc");
}
session_register("unc");
$_SESSION["unc"]=$this->usernc;
    echo "<script>alert('用户注册成功！');window.location.href='index.php';</script>";
  }else{
    echo "<script>alert('用户注册失败！');history.back();</script>";
  }
   }
 }
 
 $obj=new save_reg($_POST["usernc"],md5($_POST["userpwd1"]),$_POST["truename"],$_POST["sex"],$_POST["email"],$_POST["tel"],$_POST["qq"],$_POST["photo"],$_POST["address"]);
 $obj->savereg();
?>

Answer 1

面向對象
樓主看一下php的類那句話新建了一個save_reg對象，并調用類里的__construct方法，初始化變量。

Answer 2

我根据上面所提的代码改写了一下，但他老报错，我都不知道哪里出了问题。报错指着的地方
 $obj=new save_reg($_POST["name"],$_POST["num"],$_POST["sex"],$_POST["department"],$_POST["class1"]);
 $obj->savereg();整段代码<?php
session_start(); class save_reg{   private $name;
   private $num;
   private $sex;
   private $department;
   private $class;   public function __construct($name,$num,$sex,$department,$class1){
       $this->name=$name;
   $this->num=$num;
   $this->sex=$sex;
   $this->department=$department;
   $this->class1=$class1;
   }   public function savereg(){
      include_once("conn.php");
  $sql=mysql_query("select usernc from db_stu_info where name='".$this->name."'");
        if($info=mysql_fetch_array($sql)){
     echo "<script>alert('该学生已注册，请重新填写！');history.back();</script>";
 exit;
   } $sql = "insert into db_stu_info(id,name,num,sex,department,class1) values('','".$this->name."','".$this->num."','".$this->sex."','".$this->department."','".$this->class1."'";
$sql=mysql_query ( $sql ) or die ( "执行sql失败!" . mysql_error () ); if($sql)
{
$num = mysql_affected_rows ();
if ($num > 0) {
//header ( "Location:department.php" );
echo "<script>alert('学生信息添加成功！');window.location.href='stu_info.php';</script>";
} else {
echo "<script>alert('学生信息添加失败！');history.back();</script>";
} }
} $obj=new save_reg($_POST["name"],$_POST["num"],$_POST["sex"],$_POST["department"],$_POST["class1"]);
 $obj->savereg();
?>

Answer 3

报错信息是这个：Parse error: syntax error, unexpected T_VARIABLE, expecting T_FUNCTION in D:\wamp\www\student_zhu\stu_info_add.php on line 44