我是一名注册计算机科学课程的高中生。我们最近被分配了这个项目：
“实施密码锁类。组合锁具有26个位置标有A ..... Z的表盘。表盘需要设置三次。如果设置正确的组合，锁可以当锁再次关闭时，可以再次进入组合。如果用户将拨盘设置三次以上，则他最后三次设置确定锁是否可以打开。这项练习的一个重要部分是实施CombinationLockclass的接口。“
我已经完成并正确运行了所有内容，但我遇到了部件问题，如果锁定关闭，则可以再次打开组合。我们还没有学过循环，但我记得我的老师曾经提到它们，我认为使用循环可以解决我的问题。我在书中向前看，我尝试使用循环作为我答案的一部分。但是，我认为我最终得到了一个无限循环，我不知道如何解决这个问题。除了使用循环之外，有没有办法做到这一点？
My Tester课程如下：
public class CombinationLockTester
{
public static void main(String [] args)
{
System.out.println("*All other questions are answered with Yes or No.");
Scanner kin = new Scanner(System.in);
System.out.print("Enter what you want the combination to be. (All uppercase, with no space seperation) : ");
String userCode = kin.next();
CombinationLock userCombination = new CombinationLock(userCode);
System.out.print("Try to open the lock? : " );
String tryToOpenLockYesNo = kin.next();
if (tryToOpenLockYesNo.equals("Yes"))
{
System.out.print("Enter the lock Combination : " );
String userCombinationLockGuess = kin.next();
userCombination.openLock(userCombinationLockGuess);
if (userCombinationLockGuess.equals(userCode))
{
System.out.print("Correct Combination! Open the Lock? : ");
String openLockYesNo = kin.next();
if (openLockYesNo.equals("Yes"))
{
userCombination.unlock();
System.out.print("The lock is open and you have reaped the rewards of its contents. Will you now close the lock? : ");
String closeLockYesNo = kin.next();
if (closeLockYesNo.equals("Yes"))
{
userCombination.lock();
;
System.out.print("The lock is now closed again. Will you check again to see if you closed it? : ");
String checkLockYesNo = kin.next();
if (checkLockYesNo.equals("Yes"))
{
System.out.println("The lock is locked: " + userCombination.isItClosed());
System.out.print("Re-enter the combination? : " );
String restartYesNo = kin.next();
if (restartYesNo.equals("Yes"))
{
do
{
if (tryToOpenLockYesNo.equals("Yes"))
{
System.out.print("Enter the lock Combination : " );
String userCombinationLockGuess2 = kin.next();
userCombination.openLock(userCombinationLockGuess2);
if (userCombinationLockGuess2.equals(userCode))
{
System.out.print("Correct Combination! Open the Lock? : ");
String openLockYesNo2 = kin.next();
if (openLockYesNo2.equals("Yes"))
{
userCombination.unlock();
System.out.print("The lock is open and you have reaped the rewards of its contents. Will you now close the lock? : ");
String closeLockYesNo2 = kin.next();
if (closeLockYesNo.equals("Yes"))
{
userCombination.lock();
System.out.print("The lock is now closed again. Will you check again to see if you closed it? : ");
String checkLockYesNo2 = kin.next();
if (checkLockYesNo.equals("Yes"))
{
System.out.println("The lock is locked: " + userCombination.isItClosed());
System.out.print("Re-enter the combination? : " );
String restartYesNo2 = kin.next();
if (restartYesNo.equals("Yes"))
{
System.out.println("");
}
else
{
System.out.println("Goodbye." );
}
}
else
{
System.out.println("You did not check to see if the lock is open." );
}
}
else
{
System.out.print("You have left the lock open and unlocked.");
}
}
else
{
System.out.println("The lock is unlocked, but you chose not to open it. Are you afraid to face what's inside?");
}
}
else
{
System.out.println("Incorrect combination!");
}
}
else
{
System.out.println("The secret of the combination lock will always remain a mystery to you...");
}
}
while (userCombination.isItClosed() == true);
}
else
{
System.out.println("Goodbye." );
}
}
else
{
System.out.println("You did not check to see if the lock is open." );
}
}
else
{
System.out.print("You have left the lock open and unlocked.");
}
}
else
{
System.out.println("The lock is unlocked, but you chose not to open it. Are you afraid to face what's inside?");
}
}
else
{
System.out.println("Incorrect combination!");
}
}
else
{
System.out.println("The secret of the combination lock will always remain a mystery to you...");
}
}
班级本身是：
public class CombinationLock
{
private String code;
private String userGuess;
private boolean isLockClosed;
public CombinationLock(String pCode)
{
code = pCode;
isLockClosed = true;
}
public void openLock(String pUserGuess)
{
userGuess = pUserGuess;
if (userGuess.length() > 3)
{
userGuess = userGuess.substring(userGuess.length() - 3, userGuess.length());
}
else
{
userGuess = userGuess;
}
}
public void unlock()
{
if (userGuess.equals(code))
isLockClosed = false;
}
public void lock()
{
isLockClosed = true;
userGuess = "";
}
public boolean isItClosed()
{
return isLockClosed;
}
}
答案 0 :(得分：0)
程序的布局非常清晰，但在运行时，如果用户输入组合，然后猜测错误，程序就会停止。应该有一个while循环高于你所拥有的循环，以便在所描述的事件中，询问用户是否要进行另一次猜测。
程序应该何时结束？当他们做出3次错误的猜测或用户说他们想要结束或两者兼而有之时？需要回答这些问题，并在必要时对程序进行相应修改。虽然看起来不错。你应该能够让它工作到目前为止。
另外，请记住，您可以使用
break;
如果需要，可以打破循环。
完成后，您还应关闭扫描仪，如下所示：
kin.close();
对CombinationLockTester类进行以下几处修改会产生所需的结果：
import java.util.Scanner;
public class CombinationLockTester
{
public static void main(String [] args)
{
System.out.println("*All other questions are answered with Yes or No.");
Scanner kin = new Scanner(System.in);
System.out.print("Enter what you want the combination to be. (All uppercase, with no space seperation) : ");
String userCode = kin.next();
CombinationLock userCombination = new CombinationLock(userCode);
do
{
System.out.print("Try to open the lock? : " );
String tryToOpenLockYesNo = kin.next();
if (tryToOpenLockYesNo.equals("Yes"))
{
System.out.print("Enter the lock Combination : " );
String userCombinationLockGuess = kin.next();
userCombination.openLock(userCombinationLockGuess);
if (userCombinationLockGuess.equals(userCode))
{
System.out.print("Correct Combination! Open the Lock? : ");
String openLockYesNo = kin.next();
if (openLockYesNo.equals("Yes"))
{
userCombination.unlock();
System.out.print("The lock is open and you have reaped the rewards of its contents. Will you now close the lock? : ");
String closeLockYesNo = kin.next();
if (closeLockYesNo.equals("Yes"))
{
userCombination.lock();
;
System.out.print("The lock is now closed again. Will you check again to see if you closed it? : ");
String checkLockYesNo = kin.next();
if (checkLockYesNo.equals("Yes"))
{
System.out.println("The lock is locked: " + userCombination.isItClosed());
System.out.print("Re-enter the combination? : " );
String restartYesNo = kin.next();
if (restartYesNo.equals("Yes"))
{
if (tryToOpenLockYesNo.equals("Yes"))
{
System.out.print("Enter the lock Combination : " );
String userCombinationLockGuess2 = kin.next();
userCombination.openLock(userCombinationLockGuess2);
if (userCombinationLockGuess2.equals(userCode))
{
System.out.print("Correct Combination! Open the Lock? : ");
String openLockYesNo2 = kin.next();
if (openLockYesNo2.equals("Yes"))
{
userCombination.unlock();
System.out.print("The lock is open and you have reaped the rewards of its contents. Will you now close the lock? : ");
String closeLockYesNo2 = kin.next();
if (closeLockYesNo.equals("Yes"))
{
userCombination.lock();
System.out.print("The lock is now closed again. Will you check again to see if you closed it? : ");
String checkLockYesNo2 = kin.next();
if (checkLockYesNo.equals("Yes"))
{
System.out.println("The lock is locked: " + userCombination.isItClosed());
System.out.print("Re-enter the combination? : " );
String restartYesNo2 = kin.next();
if (restartYesNo.equals("Yes"))
{
System.out.println("");
}
else
{
System.out.println("Goodbye." );
break;
}
}
else
{
System.out.println("You did not check to see if the lock is open." );
}
}
else
{
System.out.print("You have left the lock open and unlocked.");
}
}
else
{
System.out.println("The lock is unlocked, but you chose not to open it. Are you afraid to face what's inside?");
}
}
else
{
System.out.println("Incorrect combination!");
}
}
else
{
System.out.println("The secret of the combination lock will always remain a mystery to you...");
break;
}
}
else
{
System.out.println("Goodbye." );
break;
}
}
else
{
System.out.println("You did not check to see if the lock is open." );
}
}
else
{
System.out.print("You have left the lock open and unlocked.");
}
}
else
{
System.out.println("The lock is unlocked, but you chose not to open it. Are you afraid to face what's inside?");
}
}
else
{
System.out.println("Incorrect combination!");
}
}
else
{
System.out.println("The secret of the combination lock will always remain a mystery to you...");
break;
}
}
while (userCombination.isItClosed() == true);
kin.close();
}
}
唯一需要进一步改进的是，如果用户连续3次错误，通过添加一个int计数器来防止用户再次打开锁定，每次出错都会增加（计数++）然后在
行的正确位置另一个if语句if(count==3)
{
print "no more tries allowed"
break;
}
else
{
//do nothing
}
其他部分实际上并不需要，因为其中没有任何内容。