java - 如何从 if 语句动态调用对象的引用名称？

Question

请原谅我的术语和对 Java 对象缺乏理解。我正在制作一个控制台大富翁游戏，其中包含一些类，大富翁，玩家，属性(property)等，其中大富翁有我的主要内容。我已经在 Monopoly 类中声明了 Property 和 Player 对象。玩家登陆购买的特性后，我尝试动态调用该特性的所有者，以从 Property 类将钱添加到该玩家的 .money 变量中。

我尝试使用 if 语句创建一个方法来返回一个 Player 对象，以及一个仅返回该属性所有者名称的字符串版本的方法。我的问题是我不知道如何使用它来实际用作对拥有它的玩家的引用。

属性类别

public class Property {


    boolean available=false;
    Object owner;
    int rent = 0;
    int houses = 0;
    int hotels = 0;



}

玩家等级

public class Players{
        Players(){
            int money=1500;
    }

        String name="";
        int money=0;
        int pos=0;
        int goCount=0;
        int diceDoubles=0;
        int rollsInJail=0;
        boolean outOfJailFreeCard=false;
        boolean jail=false;
        String player="";

        Scanner in=new Scanner(System.in);
        String getName(){
            name=(String) in.next();
            return name;
        }

    }

职位类别

public class Position {


public static Players playerFind(Object str, Players obj){
    if(str.equals(Monopoly.player1)){
        return Monopoly.player1;
    }
    else if(str.equals(Monopoly.player2)){
        return Monopoly.player2;
    }
    else if(str.equals(Monopoly.player3)){
        return Monopoly.player3;
    }
    else if(str.equals(Monopoly.player4)){
        return Monopoly.player4;
    }
    else if(str.equals(Monopoly.player5)){
        return Monopoly.player5;
    }
    else if(str.equals(Monopoly.player6)){
        return Monopoly.player6;
    }
    return obj;
}    

public static void place(int num, Players obj, Property prop)
    {
        Scanner in=new Scanner(System.in);



        if(num==1) {

            System.out.println(obj.name+" landed on Mediterranean Avenue.");
            if(Monopoly.mediterranean.available==true){
                System.out.println("Would you like to buy this property?(Yes or No)");
                String str = in.next();
                if(str.startsWith("y") || str.startsWith("Y")){
                    Monopoly.mediterranean.available=false;
                    Monopoly.mediterranean.owner=obj;
                    obj.money-=60;
                    System.out.println("You now own Meditarreanean Avenue!");
                    System.out.println("Your balance is "+obj.money);
                }
            }
            else{
                Players obj2 = playerFind(Monopoly.mediterranean.owner, obj);    
                System.out.println("Rent is due! "+Monopoly.mediterranean.owner+" owns this property. M2 has been subtracted from your account"
                       + " and added into "+Monopoly.mediterranean.owner+"'s bank roll.");
                Players.obj2.money+=2;
                System.out.println("Your balance is "+obj.money);

                }
        }
        else if(num==2) {
            System.out.println(obj.name+" landed on Community Chest.");


        }//etc...

垄断级

public class Monopoly {
        static Players player1 = new Players();
        static Players player2 = new Players();
        static Players player3 = new Players();
        static Players player4 = new Players();
        static Players player5 = new Players();
        static Players player6 = new Players();
        //static Position position= new Position();
        static CommunityChest chest=new CommunityChest();
        static Property property=new Property();
        static Property mediterranean=new Property();
        static Property baltic=new Property();
        static Property reading=new Property();
        static Property oriental=new Property();
        static Property vermont=new Property();
        static Property connecticut=new Property();
        static Property stCharles=new Property();
        static Property states=new Property();
        static Property virginia=new Property();
        static Property pennRail=new Property();
        static Property stJames=new Property();
        static Property tennessee=new Property();
        static Property newYork=new Property();
        static Property kentucky=new Property();
        static Property indiana=new Property();
        static Property illinois=new Property();
        static Property bAndC=new Property();
        static Property atlantic=new Property();
        static Property ventor=new Property();
        static Property marvin=new Property();
        static Property pacific=new Property();
        static Property northCar=new Property();
        static Property pennAve=new Property();
        static Property shortLine=new Property();
        static Property parkPlace=new Property();
        static Property board=new Property();
        static Property electric=new Property();
        static Property water=new Property();

        static int playerNum=intro();

public static void play(int num, int rollCount){
        int roll1=0, roll2, i=0;


        while(i<rollCount-1){
            int i1=i+1;
            System.out.println("Beginning of turn "+i1);

            if(num>0){
                turn(player1);
                System.out.println(player1.name+" money count:M"+player1.money);
            }
            if(num>1){
                turn(player2);
                System.out.println(player2.name+" money count:M"+player2.money);
            }
            if(num>2){
                turn(player3);
            }
            if(num>3){
                turn(player4);
            }
            if(num>4){
                turn(player5);
            }
            if(num==6){
                turn(player6);
            }
            System.out.println("End of turn "+i1+"\n");
            i++;

        }
    }

    public static void turn(Players obj){
        Scanner in1=new Scanner(System.in);

        int roll1=roll();
        int roll2=roll();
        obj.pos=obj.pos + roll1 + roll2;
        System.out.println(obj.name+" rolled a "+roll1+" and a "+roll2);
        if(obj.jail==false){
            System.out.println(obj.name + " has landed on "+place(obj.pos));
        }

        if(roll1!=roll2){
            obj.diceDoubles=0;
        }

        Position.place(obj.pos, obj, property);

        if(obj.jail==true){//roll while in jail, check first in case they roll doubles and continue their turn. Turn must end after going to jail
            if(obj.outOfJailFreeCard==true){//if get out of jail card, prompt to use it rightaways
                    System.out.println("You've rolled thrice doubles in a row and have ended in up jail. Luckily you have a 'Get out of jail free' card!");
                    System.out.print("Would you like to use your 'Get out of jail free' card right now?: (Y/N)");
                    String check=in1.next();
                    if(check.startsWith("y") || check.startsWith("Y")){
                        obj.pos=10;
                        obj.outOfJailFreeCard=false;
                    }
                }
            if(roll1!=roll2){
                obj.rollsInJail+=1;
                if(obj.rollsInJail==3){
                    obj.pos=10+roll1+roll2;
                    obj.money-=50;
                    obj.rollsInJail=0;
                }return;//does this break out of method to end turn??
            }
            if(roll1==roll2){
                obj.pos=10+roll1+roll2;
                obj.rollsInJail=0;
            }return;//does this break out of method to end turn??
        }

        while(roll1==roll2 && obj.diceDoubles<3){//check for doubles
            obj.diceDoubles+=1;
            if(obj.diceDoubles==3){
                obj.jail=true;
                obj.diceDoubles=0;
                System.out.println("You've rolled doubles 3 times in a row. You are now in jail!");
                break;
            }
            else{turn(obj);
            break;}
        }

        if(obj.pos>39){//pass go, collect M200
            obj.pos=obj.pos - 39;
            obj.goCount=obj.goCount+1;
            obj.money+=200;
        }

        in1.close();// close scanner
    }

    public static void main(String[] args) {

        play(playerNum, 60);
    }

我正在尝试动态查找所有者并引用实际对象实例以添加到其 .money 变量。

Answer 1

问题是您将owner作为Object引用，但它没有money字段。您需要使用 Player 类:

public class Property
{
 boolean available=false;
 Player owner;
 int rent = 0;
 int houses = 0;
 int hotels = 0;
}

然后您可以直接在两个玩家之间转移租金，例如:

Property property = Monopoly.mediterranean;
activePlayer.money-= property.rent;
property.owner.money+= property.rent;

在真正的游戏中，您将添加更多检查，例如玩家是否有足够的钱来支付租金，或者是否存在需要解决的并行性问题，但这是问题的基本解决方案。