Java - arrayLists和用户输入中的状态猜测

Question

我不太确定发生了什么事。它已经走了很长一段路，但它仍然不起作用。本练习的目的是让用户从预先确定的状态列表中猜测“您最喜欢的状态”。用户只有三次猜测，然后程序就停止了。

import java.io.*;
import java.util.*;

    class stateHelper {
    public static void getUserInput() { 
        ArrayList<String> stateList = new ArrayList<String>();
        stateList.add("Georgia");
        stateList.add("Hawaii");
        stateList.add("Arizona");
        stateList.add("New York");
        stateList.add("Montana");

        Scanner scan = new Scanner(System.in);
        String userInput = scan.next();
        System.out.println("Guess my favorite state: ");

        //loop three times
        int num = stateList.size();
        for (int i = 0; i < num ; i++) {
            // if state is in line, print you guessed it
            String st = stateList.get(i);
            System.out.println(st);
            /*if (userInput.equals(stateList.get(i))) {
                System.out.println("It is a hit."); 
                }               
            }
            if (!userInput.equals(stateList.get(i))) {
                System.out.println("It is a miss.");    
                } */
        }
    /*
    System.out.println(stateList.get(0)+
    stateList.get(1)+stateList.get(2)+stateList.get(3)+
    stateList.get(4));
    */

        }
    }

Answer 1

我可以很容易地为你解决这个问题，但我认为教你如何钓鱼会很好……就像他们说的那样。

把问题分解。

1. 从用户那里获取数字。Google java用户输入，提示:将用户输入的内容返回屏幕，你可以将数字例如1 2 3作为输入，你可以将这些数字拆分成一个数组，例如Convert a string of numbers into an array
2. Loop How can I get the user input in Java?
3. Print System.in array，将所有数字相加，并使用计数或长度的数组来跟踪分隔符。例如(1+2+3+4+7+8)/6 = average

如果您发布一些代码来演示一次尝试，我很乐意提供进一步的帮助:)

Answer 2

import java.util.Iterator;
import java.util.LinkedList;
import java.util.Scanner;


public class Averager {
    public static void main(String[] args) {
        LinkedList<Integer> numbers = new LinkedList<Integer>();

        System.out.println("Enter a number to add to the list, or QUIT to stop:");
        Scanner scanner = new Scanner(System.in);
        String userInput = scanner.next();
        while (!userInput.equalsIgnoreCase("QUIT")) {
            try {
                numbers.add(Integer.parseInt(userInput));
            } catch (NumberFormatException e)    {
                // IGNORE
            }
            userInput = scanner.next();
        }
        scanner.close();

        System.out.println("The average of these numbers is: " + average(numbers));

    }

    private static double average(LinkedList<Integer> numbers) {

        Integer top = 0, bottom = 0;

        for (Iterator<Integer> iterator = numbers.iterator(); iterator.hasNext();) {
            top += (Integer) iterator.next(); // Sum the numbers
            bottom++;  // count how many there are
        }

        if (bottom > 0) {
            return top/bottom;  // calculate the average
        }

        return 0;
    }

}