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why toString method does not work here?

this is my whole class ,I have added number 2 to the doubly linked list and then I want it to be be print in the concole but it will show this "datastructureproject.Node@f62373" thanks!

package datastructureproject;

public class DoublyLinkedList {
private Node head = new Node(0);
private Node tail = new Node(0);
private int length = 0;

public DoublyLinkedList() {

    head.setPrev(null);
    head.setNext(tail);
    tail.setPrev(head);
    tail.setNext(null);
}

public void add(int index, int value) throws IndexOutOfBoundsException {
    Node cursor = get(index);
    Node temp = new Node(value);
    temp.setPrev(cursor);
    temp.setNext(cursor.getNext());
    cursor.getNext().setPrev(temp);
    cursor.setNext(temp);
    length++;
}

private  Node get(int index) throws IndexOutOfBoundsException {
    if (index < 0 || index > length) {
        throw new IndexOutOfBoundsException();
    } else {
        Node cursor = head;
        for (int i = 0; i < index; i++) {
            cursor = cursor.getNext();
        }
        return cursor;
    }
}

public long size() {
    return length;
}

public boolean isEmpty() {
    return length == 0;
}
@Override
public String toString() {
StringBuffer result = new StringBuffer();
result.append("(head) - ");
Node temp = head;
while (temp.getNext() != tail) {
    temp = temp.getNext();
    result.append(temp.getValue() + " - ");
}
result.append("(tail)");
return result.toString();
}

public static void main(String[] args){
    DoublyLinkedList list = new DoublyLinkedList();
    list.add(0,2 );
    System.out.println(list.get(0).toString());
    }
}

EDITED: also this is my Node class, thanks!

class Node {

public int value;

public Node(){

}

public void setValue(int value) {
    this.value = value;
}
public Node next;
public Node prev;

public Node(int value) {
    this.value = value;
}

public Node(int value, Node prev, Node next) {
    this.value = value;
    setNext(next);
    setPrev(prev);
}

public void setNext(Node next) {
    this.next = next;
}

public void setPrev(Node prev) {
    this.prev = prev;
}

public Node getNext() {
    return next;
}


public Node getPrev() {
    return prev;
}

public int getValue() {
    return value;
}
}
like image 874
user329820 Avatar asked Jan 29 '26 08:01

user329820


1 Answers

You've overridden toString() on the DoubleLinkedList but you're calling it on a Node. Call list.toString() or override Node.toString() if you only want to print the node's content.

like image 168
Julien Lebosquain Avatar answered Jan 31 '26 00:01

Julien Lebosquain