EDIT: I fixed it! It was because I kept using head.method() in my class definition when all I had to do was write method().

I am attempting to design an implementation of a basic Linked List. I cannot get my code to compile or run. This is the first exercise in the Linked List Tutorial. My knowledge of coding is limited. The compile errors are copied below. I suspect it has something to do with my use of incorrect access specifiers. Corrections, tips, and general guidance are welcome.

Thank you for your time.

// Start of Class Declaration of "MyLinkedList"
class MyLinkedList {
    
    // Start of Class Declaration of "SinglyListNode" 
    public class SinglyListNode {
        int val;
        SinglyListNode next;
        
        // Constructor Declaration of SinglyListNode (i.e., Initializing SinglyListNode)
        public SinglyListNode(int x) { 
            val = x; 
        }
    }
    // End of Class Declaration of "SinglyListNode"

    // Instantiate an Object of SinglyListNode 
    // Also an instance variable of class MyLinkedList
    public SinglyListNode head;

    // Constructor Declaration of MyLinkedList (i.e., Initializing MyLinkedList)
    public MyLinkedList() {
        head = null;
    }
    
    // method 1
    private SinglyListNode getNode(int index) {
        SinglyListNode curr = head;
        for (int i = 0; i < index && curr != null; i++) {
            curr = curr.next;
        }
        return curr;
    }
    
    // method 2
    private SinglyListNode getTailNode() {
        SinglyListNode curr = head;
        while (curr != null && curr.next != null) {
            curr = curr.next;
        }
        return curr;
    }
    
    // method 3
    public int getValue(int index) {
        SinglyListNode curr =  head.getNode(index);
        return curr == null ? -1 : curr.val;
    }
    
    // method 4
    public void addNodeAtHead(int val) {
        SinglyListNode curr = new SinglyListNode(val);
        curr.next = head;
        head = curr;
    }
    
    // method 5
    public void addNodeAtTail(int val) {
        SinglyListNode curr = new SinglyListNode(val);
        head.getTailNode().next = curr;
    }
    
    // method 6
    public void addNodeAtIndex(int index, int val) {
        SinglyListNode curr = new SinglyListNode(val);
        if (head.getTailNode() == head.getNode(index)) curr = head.addNodeAtTail(val);
        if (head.getNode(index) != null) {
            curr.next = head.getNode(index);
            head.getNode(index-1).next = curr;
        }

    }
    
    // method 7
    public void deleteNodeAtIndex(int index) {
        if (head.getNode(index) != null) {
            head.getNode(index-1).next = head.getNode(index).next;
        }
    }
}

ERRORS

Line 44: error: cannot find symbol [in SinglyListNode.java] SinglyListNode curr = head.getNode(index); ^ symbol: method getNode(int) location: variable head of type MyLinkedList.SinglyListNode

Line 58: error: cannot find symbol [in SinglyListNode.java] head.getTailNode().next = curr; ^ symbol: method getTailNode() location: variable head of type MyLinkedList.SinglyListNode

Line 64: error: cannot find symbol [in SinglyListNode.java] if (head.getTailNode() == head.getNode(index)) curr = head.addNodeAtTail(val); ^ symbol: method getTailNode() location: variable head of type MyLinkedList.SinglyListNode

Line 64: error: cannot find symbol [in SinglyListNode.java] if (head.getTailNode() == head.getNode(index)) curr = head.addNodeAtTail(val); ^ symbol: method getNode(int) location: variable head of type MyLinkedList.SinglyListNode

Line 64: error: cannot find symbol [in SinglyListNode.java] if (head.getTailNode() == head.getNode(index)) curr = head.addNodeAtTail(val); ^ symbol: method addNodeAtTail(int) location: variable head of type MyLinkedList.SinglyListNode

Line 65: error: cannot find symbol [in SinglyListNode.java] if (head.getNode(index) != null) { ^ symbol: method getNode(int) location: variable head of type MyLinkedList.SinglyListNode

Line 66: error: cannot find symbol [in SinglyListNode.java] curr.next = head.getNode(index); ^ symbol: method getNode(int) location: variable head of type MyLinkedList.SinglyListNode

Line 67: error: cannot find symbol [in SinglyListNode.java] head.getNode(index-1).next = curr; ^ symbol: method getNode(int) location: variable head of type MyLinkedList.SinglyListNode

Line 16: error: cannot find symbol [in Driver.java] return Serializer.serialize(obj.get( ^ symbol: method get(int) location: variable obj of type MyLinkedList

Line 19: error: cannot find symbol [in Driver.java] obj.addAtHead( ^ symbol: method addAtHead(int) location: variable obj of type MyLinkedList Line

23: error: cannot find symbol [in Driver.java] obj.addAtTail( ^ symbol: method addAtTail(int) location: variable obj of type MyLinkedList

Line 27: error: cannot find symbol [in Driver.java] obj.addAtIndex( ^ symbol: method addAtIndex(int,int) location: variable obj of type MyLinkedList

Line 32: error: cannot find symbol [in Driver.java] obj.deleteAtIndex( ^ symbol: method deleteAtIndex(int) location: variable obj of type MyLinkedList

13 errors