再写一个猜数字的程序，用到Scanner和arraylist的API 用的是JAVA

import java.util.Scanner;
import java.util.ArrayList;


class SimpleDotcomtestDrive {//测试开发代码
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        SimpleDotcom dot = new SimpleDotcom();
        int randomNum = (int)(Math.random()*10);//产生任意数
        int n =1;
        ArrayList<String> location = new ArrayList<String>();//建立arraylist
        String a = new String(" "+(randomNum+1));/*储存正确答案*/
        location.add(a);
        String b = new String(""+(randomNum+2));
        location.add(b);
        String c = new String(""+(randomNum));
        location.add(c);
        dot.setlocationcells(location); //设置
        System.out.println("请输入一个0到10的数字: ");
        String user_Guess = scanner.nextLine();//输入数字
        String result =dot.checkYouself(user_Guess);
        while(true){
            if(result.equals("kill")){
                System.out.println("You took "+ n +"  guesses");
                break;
            }else{
                System.out.println("请输入一个0到10的数字: ");
                String user_Guess00 = scanner.nextLine();
                n=++n;
                result = dot.checkYouself(user_Guess00);
            }
        }

    }
}



/*实际代码*/

public class SimpleDotcom {
    private ArrayList<String> locationcells;

    public void setlocationcells(ArrayList<String> loc) {
       locationcells = loc;//获取值
    }

    public String checkYouself(String a){
        int guess = Integer.parseInt(a);//将字符串转化为数字
        int index = locationcells.indexOf(guess);//返回a的位置
        String result ="miss";//初始胡result
        if(index>=0){ //有匹配的数
            locationcells.remove(index); //删除匹配数字
            if(locationcells.isEmpty()){
                result = "kill";
            }else {
                result = "hit";
            }
        }
        System.out.println(result);
        return result;
    }
}

结果问题就是好像没有正确答案，我DEbug的时候发现传输arraylist到另一个对象的时候，字符串消失了，好像这样不能传一样，不管我猜啥数字都无法猜中正确答案。

你在用int 类型的 guess在String类型的locationcells中indexOf是永远找不到的