java - 使用 toString 方法代替 Print 方法

Question

如何在代码中使用 toString 方法，而不是下面的自定义 print 方法？我当前代码的输出正是它应该的，但我的导师希望我“使用 toString 并获得相同的输出”。我很困惑，不知道该怎么做。

这是我的代码:

public class LinkedListIntro {

    //print method 
    public static void print(Node temp) {
        System.out.print("[");
        while (temp.getNext() != null) {
            System.out.print(temp.getData() + ", ");
            temp = temp.getNext();
        }
        System.out.println(temp.getData() + "]");
    }

    public static void main(String[] args) {
        Node start = null;
        Node temp = null;

        for (int i = 1; i <= 5; i++) {
            if (start == null) {
                start = new Node(i);
                temp = start;
            } else {
                temp.setNext(new Node(i));
                temp = temp.getNext();
            }
        }

        //3. printing data
        print(start);

        //4. removing 4  
        temp = start;
        Node n = temp.getNext();

        while (n.getNext() != null) {
            if ((int) n.getData() == 4) {
                temp.setNext(n.getNext());
                n = null;
                break;
            }
            temp = temp.getNext();
            n = n.getNext();
        }

        //5. printing data again after removing 4
        print(start);

        //6. adding 100 between 1 and 2  
        temp = start;
        Node n1 = temp.getNext();

        while (n1.getNext() != null) {
            if ((int) temp.getData() == 1) {
                temp.setNext(new Node(100));
                temp = temp.getNext();
                temp.setNext(n1);
            }
            temp = temp.getNext();
            n1 = n1.getNext();
        }

        //7. printing data again after adding 100
        print(start);

        //8. removing first node
        temp = start;
        start = start.getNext();
        temp = null;

        //printing data after removing 1st node
        print(start);

        //9. add 0 to beginning
        temp = start;
        start = new Node(0);
        start.setNext(temp);

        //printing the final data
        print(start);
    }
}

<小时/>

public class Node<E>
{

        private E data;
        private Node next;

        public Node(E data) {
           this.data = data;
           this.next = null;
        }

        public E getData(){
            return data;
        }

        public Node getNext() {
            return next;
        }

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

        public String toString() {
            return data.toString();
        }
}

Answer 1

使用当前 print 方法中的代码在 Node 的 toString() 方法中构建输出字符串。之后，print 可以将 Node temp 参数传递给 System.out.print()，因为它使用 toString() 内部。

public static void print(Node temp) { //irrelevant method by now
   System.out.print(temp); 
}

public class Node<E>{

    private E data;
    private Node next;

    //...

    public String toString() {
       String ouput = "";
       Node node = this;
       while(node.getNext() != null) {
          output +=  node.getData() +", ";
          node = node.getNext();
       }
       return ouput; 
   }
}