问题描述

我在练习使用Java的构造函数，下面是我试图编译的类：

import java.util.*;
import java.lang.*;
public class mob{

    public Map enemies = new HashMap<String, Point>();
    public Point pn = new Point(1, 1);
    enemies.put("Peon", pn);
    public Point gn = new Point(5, 2);
    enemies.put("Goblin", gn);
    public Point tl = new Point(25, 8);
    enemies.put("Troll", tl);
    public Point oc = new Point(13, 5);
    enemies.put("Orc", oc);
    public String name;
    public int hp;
    public int dmg;

    public mob(String type){
      name=type;
      hp=enemies.get(type).getX();
      dmg=enemies.get(type).getY();
    }

    public mob(){
      name="Peon";
      hp=enemies.get("Peon").getX();
      dmg=enemies.get("Peon").getY();

    }

    void setName(String name){
            this.name=name;
    }


    public static void main(String[] args) {

      Scanner scan = new Scanner(System.in());
      System.out.System.out.println("Enter mob type:");
      String type = scan.nextln();
      if(mob.containsKey(type)){
        mob mob1 = new mob(type);
      }
      else{
        mob mob1 = new mob();
        mob1.setName(type);
      }

      System.out.println("You just spawned a "+mob1.name+", it has "+mob1.hp+" hp and "+mob1.dmg+" dmg!");
    }
}

Main方法的目的是从控制台获取一些输入，并根据输入使用来自地图的数据("敌人")或默认的**创建特定的**。但当我试图在命令提示符中编译它时，我在所有entemes.put()方法中都得到了错误，即：

mob.java:7: error: <identifier> expected
    enemies.put("Peon", pn);
               ^
mob.java:7: error: illegal start of type
    enemies.put("Peon", pn);
               ^
mob.java:9: error: <identifier> expected
    enemies.put("Goblin", gn);
               ^

等

查看了类似的问题并尝试修复问题(因此出现了所有公开声明)，但无法解决此问题...

使用Java和Java是v11.0.2

推荐答案

菱形用于告诉编译器有关泛型类的信息。但是，语法应为：

 public Map<String,Point> enemies = new HashMap<>();

和默认the enemies.put("Peon", pn);命令必须在构造函数内执行。