javascript - 调用类函数未按预期响应

Question

我在调用变量 valio 时遇到问题，当我将文本放入输入中并调用它后，控制台返回“现在已注册” 未定义”。

我有过此类调用的经验，但以前从未发生过，所以有人可以解释一下为什么这不能按我的预期工作吗？

var name = document.getElementById("name");
var email = document.getElementById("email");
var comment = document.getElementById("comment");

class User{
 constructor(username,comment,email){
  this.username = username;
  this.comment = comment;
  this.email = email;
  }
  register(){
   console.log(this.username + this.comment + " is now registered");
  }
}

var valio = new User(name.value , comment.value, email.value);

       <input id="name" type="text" value=""><br>
       <input id="email" type="text" value=""><br>
       <input id="subject" type="text" value=""><br>
       <input id="comment" type="text" value=""><br>

Answer 1

将变量 name 更改为 uname。

 var uname = document.getElementById("name");
 var email = document.getElementById("email");
 var comment = document.getElementById("comment");

 class User{
  constructor(username,comment,email){
   this.username = username;
   this.comment = comment;
   this.email = email;
   }
   register(){
    console.log(this.username + this.comment + " is now registered");
   }
 }

 var valio = new User(uname.value , comment.value, email.value);

   <input id="name" type="text" value=""><br>
   <input id="email" type="text" value=""><br>
   <input id="subject" type="text" value=""><br>
   <input id="comment" type="text" value=""><br>