使用Scala的银行系统

在这个项目中，我们将使用 Scala 构建一个简单的银行管理系统，它将执行以下任务：

1) 显示所有客户或特定客户的现有详细信息。

2) 添加或删除帐户

3) 存款或取款

4) 检查透支限额

5) 显示利息和股息金额

方法：

该程序使用了 Scala 中的继承、Scala 中的方法、If-else、方法覆盖、类和对象以及 ListBuffer 的概念。

有关上述概念的更多信息，请参阅以下链接。

a) Scala 中的继承： https://www.geeksforgeeks.org/inheritance-in-scala/

b) Scala 中的方法： https://www.geeksforgeeks.org/scala-functions-basics/

c) 方法覆盖： https://www.geeksforgeeks.org/method-overriding-in-scala/

d) 列表缓冲区：https://www.geeksforgeeks.org/scala-listbuffer/

该程序有 5 个类，分别命名为 Account、SavingAccount、CurrentAccount、Bank，以及主类 Banking_System。

1) Account：它是父类，其中包含三个方法，分别是debit()、credit()和 details() 。该类包含4个ListBuffer ，用于存储银行活期账户持有人的详细信息，按顺序存储，这样一个客户的银行账号索引及其对应的电话号码将存储在不同ListBuffer的相同索引值中。

如图所示，第一个客户详细信息将存储在所有 ListBuffer 的第一个索引中，第二个客户等也将存储。 Credit() 和 details() 方法稍后将用作覆盖方法以显示借方金额和详细信息任何客户。

下面的例子解释了它是如何工作的。

Scala

class Account{
  
  // Creating four ListBuffer which stores
  // the initial details of customer
  var name = new ListBuffer[String]()
  name += ( "Ankit", "Rohit", "Rahul" )
  var balance_current = new ListBuffer[Int]()
  balance_current += ( 20000, 30000, 40000 )
  var account_number = new ListBuffer[Int]()
  account_number += ( 1234, 5678, 9101 )
  var phone_number = new ListBuffer[Long]()
  phone_number += ( 9998273493L, 5569392838L, 6651299039L )
  
  // details() method is used to show
  // the details of all customer
  def details(): Unit ={
    println("Details of customer is\nNames of customer: " + name +
            "\nBalance list" + "is respectively: " + balance_current +
            "\nAccount number is respectively: " + account_number +
            "\nPhone number" + "is respectively: " + phone_number)
  }
  
  // Used to add money to a particular account
  def credit(): Unit = {
    var credit_amount: Int = 0
    println("Enter the account number you want to credit in: ")
  
    // readInt is used to take integer
    // value as input from user
    val acc_num1 = readInt()
  
    // indexOf() method returns the index
    // of particular element
    val index1 = account_number.indexOf(acc_num1)
    println("Enter the amount you want to credit: ")
    credit_amount = readInt()
    balance_current(index1) += credit_amount
    println("Amount added successfully\nNew Balance is: " +
             balance_current(index1))
  }
  
  // Used to withdraw money from an account
  def debit(): Unit ={
    var debit_amount : Int = 0
    println("Enter the account number " +
            "you want to withdraw from: ")
    val acc_num2 = readInt()
    val index2 = account_number.indexOf(acc_num2)
    println("Enter the amount you want to withdraw: ")
  
    debit_amount = readInt()
    balance_current(index2) -= debit_amount
    println("Money withdrawn successfully\n" +
            "Remaining balance is: " +
            balance_current(index2))
  }
}

解释：

ListBuffer: 
ListBuffer data type is used to store the values

debit():

amount_initially = 20000;
Input : 200

Output : 19800
// Initial amount was 20000. It asks to debit 200 from it 

// so final amount becomes
final = 20000 – 200 => 19800

credit():

amount_initially = 15000;

Input : 2000

Output : 17000

// Initial amount was 15000. It asks to credit 2000 in it so 

// final amount becomes
final = 15000 + 2000 => 17000
 

details():
Output : Details of all the customers

Input : Show the details of all account.

Output : 
Details of customer is

Names of customer: ListBuffer(Ankit, Rohit, Rahul)

Balance list is respectively: ListBuffer(20000, 30000, 40000)

Account number is respectively: ListBuffer(1234, 5678, 9101)

Phone number is respectively: ListBuffer(9998273493, 5569392838, 6651299039)
 

2) SavingAccount ：它是Account 类的子类，包含一个名为interest()的方法和一个名为details() 的覆盖方法。 Interest()方法用于显示任何特定帐户的利息金额。它要求用户输入帐号，然后使用下面显示的公式来显示特定帐户将获得的利息金额。

amount_initiallly + (amount_initially * 利息) / 100

Details()方法是来自类 Account 的覆盖方法，在这里用于显示任何特定客户的详细信息。早些时候它显示了所有客户的详细信息。

斯卡拉

class SavingsAccount extends Account
{
  var interest : Double = 2
  
  // Method used to calculate interest
  def interest_amount(): Unit = {
    println("Enter the account number " +
            "to see the interest amount: ")
  
    val acc_num3 = readInt()
    val index3 = account_number.indexOf(acc_num3)
    interest =  (balance_current(index3) * 2) / 100
    println("The interest amount is: "+interest)
  }
  
  // Method used to view the details of
  // any particular account
  // using method overriding
  override def details(): Unit ={
    println("Enter the account_number to see its details: ")
    val acc_num4 = readInt()
    val index4 = account_number.indexOf(acc_num4)
  
    println("Details of this account is\n" +
            "Name of customer is: " + name(index4) +
            "\nAccount number is: " + account_number(index4) +
            "\nPhone number is: " + phone_number(index4)  +
            "\nAccount balance is: " + balance_current(index4))
  }
}

解释：

interest():

Input : Account number you want to see the interest amount of the month.
1234
Output : 400.0

// Interest rate is fixed initially as fixed by

// the bank. 400 is the interest amount.

details():

Input : Enter the account_number to see its details: 
1234

Output : Details of this account is

Name of customer is: Ankit

Account number is: 1234

Phone number is: 9998273493
Account balance is: 20000

// It shows the details(name, account number,

//  phone number and current balance) 

// of the account
asked by the user.
 

3) CurrentAccount：它也是Account 类的子类，包含一个名为debit()的覆盖方法。当用户想要提款时使用此方法。它检查透支限额，这是银行设定的最低限额，要求每个账户的余额都高于透支限额，以避免现金扣除。它使用以下公式：

balance_current –withdrawn_amount < overdraft_limit

如果此公式失败，则银行将拒绝提款请求。

斯卡拉

class CurrentAccount extends Account
{
  var overdraft_limit: Int = 2000
  
  // Using method overriding
  // method used to withdraw money
  override def debit(): Unit ={
    println("Enter the account number " +
            "you want to withdraw from: ")
  
    val acc_num5 = readInt()
    val index5 = account_number.indexOf(acc_num5)
    println("Enter the amount you want to withdraw: ")
    var debit_amount = readInt()
  
    if (balance_current(index5) - debit_amount < 2000)
    {
      println("Overdraft limit exceeded " +
              "transaction declined")
    }
    else
    {
      balance_current(index5) -= debit_amount
      println("Transaction successful\n" + "" +
              "Remaining balance is: " +
               balance_current(index5))
    }
  }
}

解释：

override debit():
 

// Takes the account number as input and checks the overdraft limit.

if (balance_current(index2) – debit_amount < overdraft_limit)

{

    println(“Overdraft limit exceeded”)

 } 

else

{

    balance_current(index2)  -= debit_amount
  

     println(“Remaining balance is: “+balance_current(index2))   

}

// If for example the current balance is 30000 and 

// overdraft limit is 5000 then you cannot 

// withdraw any amount greater than 25000.
 

4) Bank :这个类也扩展了 Account 类，里面有 3 个方法，分别是opening() 和 closed() 。此类用于开仓、平仓和查找股息金额。

Opening()方法用于在银行开设任何新账户。它向用户询问其名称、集合和帐号，并询问用户初始余额。然后它使用 ListBuffer 添加功能将所有这些分别添加到不同的 ListBuffer。

List_Buffer += 元素

Closing()方法用于关闭任何现有帐户和 ListBuffer 中的所有相关详细信息。它要求用户输入帐号，然后使用 ListBuffer 的 indexOf() 方法检查该特定帐号的索引，然后分别从所有 ListBuffer 中删除该特定索引。

List_Buffer -= 元素

斯卡拉

class Bank extends Account
{
  
  // Method to open an account
  def opening(): Unit ={
  
    // readLine() method is used to
    // take a string as input from user
    var new_name = readLine("Enter the name: ")
    name += new_name
    println("Enter the opening balance: ")
    var opening_balance = readInt()
    balance_current += opening_balance
    account_number += 1908
    println("Account added successfully")
  }
  
  // Method used to close an existing account
  def closing(): Unit ={
    println("Enter the account number: ")
    val acc_num6 = readInt()
    val index6 = account_number.indexOf(acc_num6)
    name -= name(index6)
    balance_current -= balance_current(index6)
    account_number -= account_number(index6)
    println("Account removed successfully")
  }
}

解释：

opening():

Input : Takes the name, account number and initial balance you want to deposit as input

Output : Account added successfully

// It asks user to enter the account number and 

// then checks the index of that particular account

// number using indexOf() method of ListBuffer 

// and then deletes that particular index 
from

// all the ListBuffer respectively.
 

closing():

Input : Takes the account number as input

Output : Account removed successfully

// It also uses the similar method showed above in opening() case.
 

5）银行系统/主类：作为主类工作，有对象和if-else语句。这个类作为主函数，代码执行从这里开始。它包含 4 个对象，每个类和选择语句一个。选择语句用于使代码由用户驱动和菜单驱动。将检查用户输入的选择并返回该特定功能。为此，它使用 if-else 语句。

它为每个类和 if-else 语句提供 1 个对象来执行不同的任务。

下面是上述问题的实现：

斯卡拉

// Scala program for Banking System
import scala.collection.mutable.ListBuffer
import scala.io.StdIn.{readInt, readLine}
  
class Account{
  
  // Creating four ListBuffer which stores
  // the initial details of customer
  var name = new ListBuffer[String]()
  name += ( "Ankit", "Rohit", "Rahul" )
  var balance_current = new ListBuffer[Int]()
  balance_current += ( 20000, 30000, 40000 )
  var account_number = new ListBuffer[Int]()
  account_number += ( 1234, 5678, 9101 )
  var phone_number = new ListBuffer[Long]()
  phone_number += ( 9998273493L, 5569392838L, 6651299039L )
  
  // details() method is used to show
  // the details of all customer
  def details(): Unit ={
    println("Details of customer is\nNames of customer: " + name +
            "\nBalance list" + "is respectively: " + balance_current +
            "\nAccount number is respectively: " + account_number +
            "\nPhone number" + "is respectively: " + phone_number)
  }
  
  // Used to add money to a particular account
  def credit(): Unit = {
    var credit_amount: Int = 0
    println("Enter the account number you want to credit in: ")
  
    // readInt is used to take integer
    // value as input from user
    val acc_num1 = readInt()
  
    // indexOf() method returns the index
    // of particular element
    val index1 = account_number.indexOf(acc_num1)
    println("Enter the amount you want to credit: ")
    credit_amount = readInt()
    balance_current(index1) += credit_amount
    println("Amount added successfully\nNew Balance is: " +
             balance_current(index1))
  }
  
  // Used to withdraw money from an account
  def debit(): Unit ={
    var debit_amount : Int = 0
    println("Enter the account number " +
            "you want to withdraw from: ")
    val acc_num2 = readInt()
    val index2 = account_number.indexOf(acc_num2)
    println("Enter the amount you want to withdraw: ")
  
    debit_amount = readInt()
    balance_current(index2) -= debit_amount
    println("Money withdrawn successfully\n" +
            "Remaining balance is: " +
            balance_current(index2))
  }
}
  
// Child class of class Account()
class SavingsAccount extends Account
{
  var interest : Double = 2
  
  // Method used to calculate interest
  def interest_amount(): Unit = {
    println("Enter the account number " +
            "to see the interest amount: ")
  
    val acc_num3 = readInt()
    val index3 = account_number.indexOf(acc_num3)
    interest =  (balance_current(index3) * 2) / 100
    println("The interest amount is: "+interest)
  }
  
  // Method used to view the details of
  // any particular account
  // using method overriding
  override def details(): Unit ={
    println("Enter the account_number to see its details: ")
    val acc_num4 = readInt()
    val index4 = account_number.indexOf(acc_num4)
  
    println("Details of this account is\n" +
            "Name of customer is: " + name(index4) +
            "\nAccount number is: " + account_number(index4) +
            "\nPhone number is: " + phone_number(index4)  +
            "\nAccount balance is: " + balance_current(index4))
  }
}
  
// Child class of class Account()
class CurrentAccount extends Account
{
  var overdraft_limit: Int = 2000
  
  // Using method overriding
  // method used to withdraw money
  override def debit(): Unit ={
    println("Enter the account number " +
            "you want to withdraw from: ")
  
    val acc_num5 = readInt()
    val index5 = account_number.indexOf(acc_num5)
    println("Enter the amount you want to withdraw: ")
    var debit_amount = readInt()
  
    if (balance_current(index5) - debit_amount < 2000)
    {
      println("Overdraft limit exceeded " +
              "transaction declined")
    }
    else
    {
      balance_current(index5) -= debit_amount
      println("Transaction successful\n" + "" +
              "Remaining balance is: " +
               balance_current(index5))
    }
  }
}
  
// Child class of class Account()
class Bank extends Account
{
  
  // Method to open an account
  def opening(): Unit ={
  
    // readLine() method is used to
    // take a string as input from user
    var new_name = readLine("Enter the name: ")
    name += new_name
    println("Enter the opening balance: ")
    var opening_balance = readInt()
    balance_current += opening_balance
    account_number += 1908
    println("Account added successfully")
  }
  
  // Method used to close an existing account
  def closing(): Unit ={
    println("Enter the account number: ")
    val acc_num6 = readInt()
    val index6 = account_number.indexOf(acc_num6)
    name -= name(index6)
    balance_current -= balance_current(index6)
    account_number -= account_number(index6)
    println("Account removed successfully")
  }
}
  
// Main class
object Banking_System
{
  def main(args: Array[String]): Unit = {
  
    // Object of all classes
    val obj1 = new Account()
    val obj2 = new SavingsAccount()
    val obj3 = new CurrentAccount()
    val obj4 = new Bank()
  
    println("Enter 1 for account details, " +
            "2 for SavingsAccount, " +
            "3 for CurrentAccount and " +
            "4 for closing or opening account")
  
    val choice = readInt()
    if (choice == 1)
    {
      obj1.details()
    }
  
    if (choice == 2)
    {
      println("Enter 1 for checking the interest " +
              "amount and 2 if you want to see the " +
              "details of any particular account: ")
  
      val choice1 = readInt()
      if (choice1 == 1)
      {
        obj2.interest_amount()
      }
      else if (choice == 2)
      {
        obj2.details()
      }
    }
  
    if(choice == 3)
    {
      println("Enter 1 for credit and 2 for debit: ")
      val choice2 = readInt()
  
      if (choice2 == 1)
      {
        obj3.credit()
      }
      if (choice2 == 2)
      {
        obj3.debit()
      }
    }
  
    if (choice == 4)
    {
      println("Enter 1 for opening account " +
              "and 2 for closing an account: ")
  
      val choice3 = readInt()
      if(choice3 == 1)
      {
        obj4.opening()
      }
      else
      {
        obj4.closing()
      }
    }
  }
}

输出：

1)Details:Enter 1 for account details, 2 for SavingsAccount, 3 for CurrentAccount 
and 4 for closing or opening account
1
Details of customer is
Names of customer: ListBuffer(Ankit, Rohit, Rahul)
Balance list is respectively: ListBuffer(20000, 30000, 40000)
Account number is respectively: ListBuffer(1234, 5678, 9101)
Phone number is respectively: ListBuffer(9998273493, 5569392838, 6651299039)
----------------------------------------------------------------------------------------

2)SavingsAccount: Input1 
Enter 1 for account details, 2 for SavingsAccount, 
3 for CurrentAccount and 4 for closing or opening account
2
Enter 1 for checking the interest amount and 2 if you want to see the details of any particular account: 
1
Enter the account number to see the interest amount: 
1234
The interest amount is: 400.0
Input2
Enter 1 for account details, 2 for SavingsAccount, 3 for CurrentAccount and 4 for closing or opening account
2
Enter 1 for checking the interest amount and 2 if you want to see the details of any particular account: 
2
Enter the account_number to see its details: 
1234
Details of this account is
Name of customer is: Ankit
Account number is: 1234
Phone number is: 9998273493
Account balance is: 20000
---------------------------------------------------------------------------------------

3)CurrentAccount: Input1
Enter 1 for account details, 2 for SavingsAccount, 3 for CurrentAccount and 4 for closing or opening account
3
Enter 1 for credit and 2 for debit: 
1
Enter the account number you want to credit in: 
1234
Enter the amount you want to credit: 
2000
Amount added successfully
New Balance is: 22000
Input2
Enter 1 for account details, 2 for SavingsAccount, 3 for CurrentAccount and 4 for closing or opening account
3
Enter 1 for credit and 2 for debit: 
2
Enter the account number you want to withdraw from: 
1234
Enter the amount you want to withdraw: 
2000
Transaction successful
Remaining balance is: 18000
---------------------------------------------------------------------------------------

4)Bank: Input1
Enter 1 for account details, 2 for SavingsAccount, 3 for CurrentAccount and 4 for closing or opening account
4
Enter 1 for opening account and 2 for closing an account: 
1
Enter the name: Anshul
Enter the opening balance: 
20000
Account added successfully
Input2
Enter 1 for account details, 2 for SavingsAccount, 3 for CurrentAccount and 4 for closing or opening account
4
Enter 1 for opening account and 2 for closing an account: 
2
Enter the account number: 
1234
Account removed successfully