正在打印的最后一个对象无论如何

Question

我有这个人类与一些方法来添加，删除和查看你的朋友。出于某种原因，当我想要查看我的朋友时，尽管我认为我以正确的方式调用了正确的方法，但无论方法调用中的对象规范如何，都会打印最后一个Person对象（它是carl）。问题是什么？

这里是代码：

package person; 

public class Person { 
    private static String name; 
    private static String friends; 

    public static void main(String[] args) { 

     Person ted = new Person ("ted"); 
     Person jim = new Person ("jim"); 
     Person todd = new Person ("todd"); 
     Person tom = new Person ("tom"); 
     Person carl = new Person ("carl"); 

     // apparently I'm making a mistake here... 
     jim.addFriend(zack); 
     System.out.println(jim.getFriends()); 
    } 
    public Person (String aName) { 
     name = aName; 
     friends = ""; 
    } 
    public static void addFriend(Person friend) { 

     friends = friends + friend.name + " "; 
    } 
    public static void unFriend (Person nonFriend) { 
     friends = friends.replace(nonFriend.name + " ", ""); 
    } 
    public static String getFriends() { 
     return friends; 
    } 

} 

Answer 1

您正在使用静态变量。请试试这个。

package person; 

public class Person { 
    private String name; 
    private String friends; 

    public static void main(String[] args) { 

     Person ted = new Person ("ted"); 
     Person jim = new Person ("jim"); 
     Person todd = new Person ("todd"); 
     Person tom = new Person ("tom"); 
     Person carl = new Person ("carl"); 

     // apparently I'm making a mistake here... 
     jim.addFriend(zack); 
     System.out.println(jim.getFriends()); 
    } 
    public Person (String aName) { 
     name = aName; 
     friends = ""; 
    } 
    public void addFriend(Person friend) { 

     friends = friends + friend.name + " "; 
    } 
    public void unFriend (Person nonFriend) { 
     friends = friends.replace(nonFriend.name + " ", ""); 
    } 
    public String getFriends() { 
     return friends; 
    } 

} 

Answer 2

让

private static String name; 
private static String friends; 

要

private String name; 
private String friends; 

，并通过去除static太

public void addFriend(Person friend) { 

     friends = friends + friend.name + " "; 
    } 
    public void unFriend (Person nonFriend) { 
     friends = friends.replace(nonFriend.name + " ", ""); 
    } 
    public String getFriends() { 
     return friends; 
    }