java - Java孤儿案

Question

孤立案例错误以下是将在程序中完成的任务:-

1. 接受客户存款并更新余额。
2. 显示余额。
3. 计算并存入复利。
4. 允许提款并更新余额。
5. 检查最低余额，如有必要，处以罚款并更新余额

我收到“孤立案例”错误

情况1:S1.Display();

情况1:S2.Display();

请帮忙。这是代码:

import java.util.*;

class Account

{
 String custname;

 double accno;

 double bal;


 Account(String c, double a, double b)

 {custname = c;

  accno = a;

  bal = b;
 }



 void Display()

 {System.out.println("Account Holder: "+custname);

  System.out.println("Account Number "+accno);
  System.out.println("Balance : "+bal); 
 }



 void Deposit()

 {double dep;

  Scanner sc = new Scanner(System.in);

  System.out.println("Please Enter the amount your want to deposit:");

  dep = sc.nextDouble();

  bal = bal + dep;

  System.out.println("Updated Details....");

  Display();
 }


 void Withdraw()

 {double wth;

  Scanner sc = new Scanner(System.in);

  System.out.println("Please enter the amount you want to withdraw");

  wth = sc.NextDouble();

  bal = bal - wth;

  System.out.println("Updated details....");

  Display();

 }

}



class SavAccount extends Account

{ String acctype;


  SavAccount(String c, double a, double b)
 {Super(c, a, b);

  acctype = "Savings";

 }



 void ComInt()

 {int months;

  Scanner sc = new Scanner(System.in);

  System.out.println("Please enter the duration of the account in months");

  months = sc.NextInt();

  double rate, inte;
  rate = 0.04;

  inte = months *rate * bal;

  bal = bal + inte;

  System.out.println("Compund Interest : "+inte);
 }



 void Display()

 {System.out.println("Account Holder: "+custname);

  System.out.println("Account Number "+accno);

  ComInt();

 System.out.println("Balance : "+bal);

  System.out.println("Account Type: "+acctype);

 }

}



class CurAccount extends Account

{String acctype;

 CurAccount(String c, double a, double b)

 {Super(c, a, b);

  acctype = "Current";

 } 


 void Penalty()
 { 
  if(bal<5000.00)

  {bal = bal - 100.00;
   System.out.println("Fine deducted Rs.100/-");

  }
 }

 void Display()

 {System.out.println("Account Holder: "+custname);

  System.out.println("Account Number "+accno);

  Penalty();

 System.out.println("Balance : "+bal);

  System.out.println("Account Type: "+acctype);

  if(bal<=5000.00)

  {System.out.println("Warning!! Please maintain balance above Rs.5000/-");

  }
 }


}
class Accmain
{public static void main(Strings args[])

 {SavAccount S1 = new SavAccount("Aniruddha", 134.00, 15000.00)
;
  CurAccount S2 = new CurAccount("Tyrel" , 135.00, 6000.00);

  int num = 2;


  String c = "y";

  int n;

  double temp;
  double accs[] = new double[10];

  accs[0] = S1.accno;

  accs[1] = S2.accno;

  Scanner sc = new Scanner(System.in);

  while (c == "y");

  {System.out.println("Please enter your Account number:");

   temp = sc.nextDouble();

   if(accs[0] == temp)

   {System.out.println("Welcome "+ S1.custname);

    System.out.println("Account Type: "+ S1.acctype);

    System.out.println("1.Display");

    System.out.println("2.Withdraw");

    System.out.println("3.Deposit");

    n = sc.nextInt();

    Switch(n)
;
    {
     case 1 : S1.Display();

     case 2 : S1.Withdraw();

     case 3 : S1.Deposit();

    default :System.out.println("Bad Choice ");

     c = "n";

   }

   }
   else if(accs[1] == temp)

   {System.out.println("Welcome "+ S2.custname);

    System.out.println("Account Type: "+ S2.acctype);

    System.out.println("1.Display");

    System.out.println("2.Withdraw");

    System.out.println("3.Deposit");

    n = sc.nextInt()
;
    Switch(n);
    {
     case 1 : S2.Display();

     case 2 : S2.Withdraw();

     case 3 : S2.Deposit();
     default :System.out.println("Bad Choice ");

     c = "n";
    }

   }

  } 

 }



} 

Answer 1

几个问题。

1) 额外的 ;最终使得切换在该语句上立即完成。

Switch(n); <--

显然所有病例都变成了孤儿。

如果删除 Switch(n) 之后的冒号你会没事的。

 Switch(n)
    {
     case 1 : S1.Display();

     case 2 : S1.Withdraw();

2) 之后你又遇到了另一个问题。每个案例之后您都需要休息。否则，即使找到匹配项，您的交换机也会执行所有情况。要停止该情况，请在每个案例后添加 break

  Switch(n)
        {
         case 1 : S1.Display(); break;

         case 2 : S1.Withdraw();break;
          ...

3) 当您写 c == "y" 时比较引用而不是相等。

您需要使用equals()检查字符串相等性的方法

阅读How do I compare strings in Java?

4) 该行 Super(c, a, b);不会编译为 S一定是小写的。 Java 区分大小写。