Need help with his code. It's not compiling

import java.util.Scanner;

//Class Node
class Node {
  protected int data;
  protected Node link;


//Constructor
  public Node() {
    link = null;
    data = 0;
  }

//Constructor
  public Node(int d, Node n) {
    data = d;
    link = n;
  }



//Function to set link to next Node
  public void setLink(Node n) {
    link = n;
  }


//Function to set data to current Node
  public void setData(int d) {
    data = d;
  }


//Function tp get link to next node
  public Node getLink() {
    return link;
  }


//Function to get data from current Node
  public int getData() {
    return data;
  }
}



// Class linkedList
class linkedList {
  protected Node start;
  protected Node end;
  public int size;


// Constructor
  public linkedList() {
    start = null;
    end = null;
    size = 0;
  }



// Function to check if list is empty
  public boolean isEmpty() {
    return start == null;
  }

  public int getSize() {
    return size;
  }


// Function to insert an element at beginning
  public void insertAtStart(int val){
    Node nptr = new Node(val, null);
    size++;
    if(start == null) {
      start = nptr;
      end = start;
    }
    else {
      nptr.setLink(start);
      start = nptr;
    }
  }


//Functions to insert an element at end 
  public void insertAtEnd(int val) {
    Node nptr = new Node(val, null);
    size++;
    if(start == null) {
      start = nptr;
      end = start;
    }
    else {
      end.setLink(nptr);
      end = nptr;
    }
  }

  public void insertAtPos(int val, int pos) {
    Node nptr = new Node(val, null);
    size++;
    if(start == null){
      start = nptr;
      end = start;
    }
    else {
      nptr.setLink(start);
      start = nptr;
    }

  }

  public void insertAtEnd(int val) {
    Node nptr = new Node(val, null);
    size++;
    if(start == null) {
      start = nptr;
      end = start;
  }
    else {
    end.setLink(nptr);
    end = nptr;
    }
  }

  public void insertAtPos(int val, int pos) {
    Node nptr = new Node(val, null);
    Node ptr = start;
    pos = pos - 1;
    for(int i = 1; i < size; i++){
      if(i == pos) {
        Node tmp = ptr.getLink();
        ptr.setLink(tmp);
        nptr.setLink(tmp);
        break;
      }
      ptr = ptr.getLink();
    }
    size++;
  }

  public void deleteAtPos(int pos){
    if (pos == 1){
      start = start.getLink();
      size--;
      return;
    }
    if(pos == size){
      Node s = start;
      Node t = start;
      while (s != end){
        t = s;
        s = s.getLink();
      }
      end = t;
      end.setLink(null);
      size--;
      return;
    }
    Node ptr = start;
    pos = pos - 1;
    for(int i = 1; i < size - 1; i++){
      if (i == pos){
        Node tmp = ptr.getLink();
        tmp = tmp.getLink();
        ptr.setLink(tmp);
        break;
      }
      ptr = ptr.getLink();
    }
    size--;
  }

  public void display() {
    System.out.print("\nSingly Linked List = ");
    if (size = 0){
      System.out.print("empty\n");
      return;
    }
    if(start.getLink() == null){
      System.out.println(start.getData());
      return;
    }

    Node ptr = start;
    System.out.print(start.getData() + "->");
    ptr = start.getLink();
    while (ptr.getLink() != null) {
      System.out.print(ptr.getData() + "->");
      ptr = ptr.getLink();
    }
    System.out.print(ptr.getData() + "\n");
  }
}

public class SinglyLinkedList {
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    linkedList list = new linkedList();
    System.out.println("Singly Linked List Test\n");
    char ch;

    do{
      System.out.println("\nSingly Linked List Operations\n");
      System.out.println("1. insert at the beginning");
      System.out.println("2.insert at the end");
      System.out.println("3.insert at position");
      System.out.println("4.delete at position");
      System.out.println("5.check empty");
      System.out.println("6.get size");

      int choice = scan.nextInt();
      switch(choice){
        case 1:
          System.out.println("Enter integer element to insert");
          list.insertAtStart(scan.nextInt());
          break;
        case 2:
          System.out.println("Enter integer element to insert");
          list.insertAtEnd(scan.nextInt());
          break;
        case 3:
          System.out.println("Enter integer element to insert");
          int num = scan.nextInt();
          System.out.println("Enter position");
          int pos = scan.nextInt();
          if(pos <= 1 || pos > list.getSize())
            System.out.println("Invalid position\n");
          else
            list.insertAtPos(num, pos);
            break;
        case 4:
          System.out.println("Enter position");
          int p = scan.nextInt();
          if(p < 1 || p > list.getSize())
            System.out.println("Invalid position\n");
          else
            list.deleteAtPos(p);
            break;
        case 5:
            System.out.println("Empty status = " + list.isEmpty());
            break;
        case 6:
            System.out.println("Size = " + list.getSize() + "\n");
            break;
        default:
            System.out.println("Wrong Entry\n");
            break;
      }
      list.display();
      System.out.println("\nDo you want to continue (TYPE y or n)\n");
      ch = scan.next().charAt(0);
    }while(ch == 'Y' || ch == 'y');
  }
}