Java-For循环中的2-Do-While循环

Question

我是编程的新手，请原谅我有限的理解。 本质上，我正在为一个学校项目创建一个记忆游戏。 我想在一个像这样工作的for循环中执行2个do-while循环：将提示用户输入4个随机字母，这将在第一个do-while循环中完成，第二个do-while循环将要求用户重新输入他们最初输入的短语。

所以我的第一个问题是，为什么只执行第一个do-while？ 我假设for循环执行第一次操作，然后根据我的参数重复执行，因此第二个将永远不会执行，但是，我很感谢理解原因的任何帮助，并可能重新格式化了程序。

我的第二个问题是，我想拥有一种计分计数器，可以按正确顺序为每个正确猜出的字母给用户10分，为错误顺序中的每个不正确字符扣除10分。 我将如何去做，我必须利用什么来使之成为可能？

最后，如果有人能指出隐藏用户输入字母的方法，我将不胜感激。

任何其他使我的程序更有效的建议将不胜感激！

import java.util.Scanner;
import java.lang.String;

public class MemoryGame { 
public static void main(String[]args){
Scanner input = new Scanner(System.in); 
int choice;

System.out.println("This is a M E M O R Y  G A M E"); 
System.out.println("Press '1' for instructions");
System.out.println("Press '2' to play");

choice = input.nextInt(); //Checks user selection and redirects
if (choice == 1) {
  Instructions();
} else {
  playGame();
}
input.close();
}

public static void Instructions() { //Instructions method
int choice; 
Scanner input = new Scanner(System.in);

System.out.println("This is a memory game. Below are a few instructions     on how to play as well as few hints, and tricks");
System.out.println("> Players wlll be given a input box to input a given number of letters or numbers depending on the stage level.");
System.out.println("> To progress and gain points, users must sucessfully recall the set phrase that they have inputted.");
System.out.println("> Based on the number of correct letters, users will gain points and progress through a set of levels that increase in difficulty.");
System.out.println("> Upon making 3 incorrect character selections users will be displayed a 'Game Over' screen from which they may:");
System.out.println("1. Head to the main menu");
System.out.println("2. View the instructions");
System.out.println("3. Play again");
System.out.println("If users successfully oomplete 5 stages with no errors, they will be prompted a challenge level in which more characters will be required");
System.out.println(" ");
System.out.println("1. Press '1' to return to play");

choice = input.nextInt(); 
if (choice == 1) {
  playGame();
}
input.close(); //Closes input. 
}

public static void playGame() { 
int userNumbers1; 
int userNumbers2; 
String userLetters1;
String userLetters2;
int scorePlayer;
int livesPlayer = 3;
int stagePlayer = 4;
int stageGeneral = 1;
Scanner input = new Scanner(System.in);

System.out.println("This is the M E M O R Y  G A M E");
System.out.println("Stage 1 initializing . . .");
System.out.println("Please enter " + stagePlayer + " letters of your   choice.");

for (int i = 0; i <= 10; i++) {

do {
userLetters1 = input.nextLine();
userLetters1 = userLetters1.toLowerCase(); userLetters1.trim();
if (userLetters1.length()==stagePlayer) {
  System.out.println (". . .!");  
  stagePlayer = stagePlayer + 2;
  stageGeneral = stageGeneral + 1;
} else {
  System.out.println("Please enter " + stagePlayer + " letters");
}
}
while ( userLetters1.length() != stagePlayer);

do {
userLetters2 = input.nextLine();
userLetters2 = userLetters2.toLowerCase(); userLetters2.trim();
if (userLetters2.length()==userLetters1.length() && userLetters2.equals (userLetters1)) {
  System.out.println (". . .");
  System.out.println ("Great job!");
  System.out.println("Stage " + stageGeneral + " initializing . . .");
  System.out.println("Please enter " + stagePlayer + " letters of your choice.");
} else {
  System.out.println ("Please enter " + userLetters1.length() + "letters that were previously entered.");
}
}
while ( userLetters1.length() != userLetters2.length());
}
}
}

Answer 1

不要假设 改为调试。 逐行查看发生的情况，并确定第一次失败永远不会退出的原因。 如果退出了，我看不出为什么第二个没有执行。

对于第二个问题，我会鼓励阅读String类文档。 您所需要做的就是遍历字符，并对copmarisions的结果做出相应的反应。

在控制台中，要隐藏以前的用户输入，可以清除屏幕，例如：

Runtime.getRuntime().exex("cls);