Java - 将值分配给实例变量时，应在此标记之后使用 VariableDeclaratorID

Question

我正在研究来自 this 的链表来自加州大学伯克利分校的视频。然而，当我尝试在我的 Eclipse 编译器中输入相同的版本时，就像这样......

public class CreateLinkedList{

    public class Node{
        String PlayerName;
        Node next;
    }


    Node first = new Node();
    Node second = new Node();
    Node third = new Node();

    first.PlayerName = "Sanchez";
    second.PlayerName = "Ozil";
    third.PlayerName = "Welbeck";


    public static void main(String[] args) {

    }
}

我在以下行中收到错误“ token “PlayerName”的语法错误，此 token 后应为 VariableDeclaratorID”

first.PlayerName = "Sanchez";
second.PlayerName = "Ozil";
third.PlayerName = "Welbeck";

谁能解释我哪里出错了？

Answer 1

评论 nested class definitions ...如果您想从静态上下文中设置属性...您需要一个静态类。

public class CreateLinkedList{

static class Node{
    String playerName;
    Node next;
}

public static void main(String[] args) {

    Node first = new Node();
    Node second = new Node();
    Node third = new Node();

    first.playerName = "Sanchez";
    second.playerName = "Ozil";
    third.playerName = "Welbeck";

    System.out.println("First is : " + first.playerName);
    System.out.println("Second is : " + second.playerName);
    System.out.println("Third is : " + third.playerName);

    }
}

如果您希望将您的内部类保留为嵌套的公共(public)类，那么您需要先实例化上层类。

public class CreateLinkedList {

    public class Node {
        String playerName;
        Node next;
    }

    public static void main( String[] args ) {

        Node first = new CreateLinkedList().new Node();
        Node second = new CreateLinkedList().new Node();
        Node third = new CreateLinkedList().new Node();

        first.playerName = "Sanchez";
        second.playerName = "Ozil";
        third.playerName = "Welbeck";

        System.out.println( "First is : " + first.playerName );
        System.out.println( "Second is : " + second.playerName );
        System.out.println( "Third is : " + third.playerName );

    }
}