Output 不会打印链表中的所有列表。 使用 java

Question

我尝试使用链表制作学生注册系统列表。 因此，您可以将名称添加到列表中，但问题是 output 仅打印用户添加的名字而不是全部。

我尝试添加迈克尔、凯特和罗斯的名字。 但 output 只显示迈克尔。

output：

*****学生课程注册系统*****

- - - - - - - - - - 菜单 - - - - - - - - -

1. 将新学生添加到课程中
2. 删除/撤销注册
3. 显示学生信息
4. 编辑学生数据
5. 搜索课程中的学生
6. 出口

您的选择：3

学生姓名：迈克尔

请帮我显示我添加到列表中的所有名称。 先感谢您。 你的帮助对我真的很有帮助！

public class LinkedList2nd {
    Node head; 

    static class Node 
{   
   // Data fields for Node   
   Object info;  // data stored in the node
   Node link;         // link to next node

   // Methods
   // Constructors
   // postcondition: Creates a new empty node.
   public Node() {
     info = null;
     link = null;

   }

   // postcondition: Creates a new node storing obj.
   public Node(Object obj) {
     info = obj;
     link = null;
   }

   // postcondition: Creates a new node storing obj 
   //   and linked to node referenced by next.
   public Node(Object obj, Node next) {
     info = obj;
     link = next;
   } 
   // accessors

   public Object getInfo() 
   {
      return info;
   }

   public Node getLink() 
   {
      return link;
   }


   // mutators
   public void setInfo(Object newInfo) 
   {
      info = newInfo;
   }

   public void setLink(Node newLink) 
   {
      link = newLink;
   }
} 

    public static LinkedList2nd insert(LinkedList2nd list,Object info){
        Node newNode = new Node(info);
        if(list.head == null){
            list.head = newNode;
        }
        else {
          //inserting last node 
            Node current = list.head;
           while(current.getLink() != null){
            current = current.getLink();
            current.setLink(newNode); }//while 

            }//else

        return list;
    }

    public static void printList(LinkedList2nd list){
        Node current = list.head; 

        System.out.println("Student Name\n--------------");

        while(current != null){
          System.out.println(current.getInfo() + " ");
          current = current.link;//to next node 

        }//while

        System.out.println("\n");
    }

}



//`enter code here`MAIN CLASS : 


public class Main {
//STUDENT COURSE REGISTRATION SYSTEM 
    static LinkedList2nd name = new LinkedList2nd();
    //static LinkedList matric = new LinkedList();
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        int choice;
        do {
            menu();
            System.out.print("Your choice:");
            choice=sc.nextInt();
            if (choice==0){
              System.out.println("Thank you and Good Bye.");
            break;
              }
            else 
            processChoice(choice);
            } while (choice !=0);
          }//end main



    static void menu(){
        System.out.println("*****STUDENT COURSE REGISTRATION SYSTEM*****");
        System.out.println("********************************************");
        System.out.println("-------------------- MENU ------------------\n"
                        +"1. ADD NEW STUDENT TO COURSE\n"
                        +"2. REMOVE/WITHDRAW ENROLLMENT\n"
                        +"3. DISPLAY STUDENT INFORMATION\n"
                        +"4. EDIT STUDENT DATA\n"
                        +"5. SEARCH STUDENT IN THE COURSE\n"
                        +"0. EXIT");
          }//menu

    static void processChoice(int choice){
        switch (choice) {
            case 1:
                addStudent();
                break;

            case 3:
                displayList();
                break; 

            default:
                break;
        }    
    }

    static void addStudent(){
        Scanner read = new Scanner(System.in);
        System.out.println("Enter Student Name : ");
        String inputName = read.nextLine();
        name.insert(name, inputName);


    }

    static void displayList(){
        name.printList(name);

    }

    }//class 

Answer 1

在您当前的插入方法中，您将所有节点的链接设置为 newNode。 您应该将 set 调用移出循环

       while(current.getLink() != null){
        current = current.getLink();
        current.setLink(newNode); }//while 

        }//else

已更正

       while(current.getLink() != null){
        current = current.getLink();

        }//else
        current.setLink(newNode);