如何在每次运行程序时使我的总和准确无误？

Question

这是我分手的Black Jack程序代码的一部分。这只是向玩家发放两张牌然后提示另一张牌并总计总和的部分。每当玩家选择另一张牌时，我的总和就会混乱，因为我的公式会将新号码添加到原来的两张牌，现在是前两张牌和第一张新牌。

import java.util.Scanner;
import java.util.Random;

public class DealToPlayer 
{

    public static void main(String[] args) 
    {
        String input;
        char choice; 
        int sum; 
        int card1; 
        int card2; 
        int newCard;  

        @SuppressWarnings("resource")
        Scanner keyboard = new Scanner(System.in); 

        Random randomNumbers = new Random(); 

        card1 = randomNumbers.nextInt(13)+1; 
        card2 = randomNumbers.nextInt(13)+1; 

        System.out.println("First Card: " +card1 + " Second Card: " +card2); 

        System.out.println("Would you like another card?"); 
        input = keyboard.nextLine(); 
        choice = input.charAt(0); 

        do 
        {
            newCard = randomNumbers.nextInt(13)+1; 
            System.out.println("New card: " +newCard); 

            sum = card1 + card2 + newCard; 
            System.out.println("Sum: " +sum); 

            System.out.println("Would you like another card?"); 
            input = keyboard.nextLine(); 
            choice = input.charAt(0); 

        }while (choice == 'Y' || choice == 'y'); 

    }

}

Answer 1

从循环中提取 card1 + card2 ：

sum = card1 + card2;
do 
{
    newCard = randomNumbers.nextInt(13)+1; 
    System.out.println("New card: " +newCard); 

    sum = sum + newCard; 
    System.out.println("Sum: " +sum); 

这样每个循环只会将新卡值添加到总和中。