Question

我正在制定一个简单的银行业务计划，我可以创建一个账户，并从账户存款和取款。

我遇到问题，我的代码在以下情况下显示错误消息：

我试图提取比我更多的钱。
当我已经有负余额时撤回资金。

退出资金不足的帐户时，应提示InsufficientFundsError。当我做出否定撤回时，它应该提示NegativeAmountError。

这是类文件：

class BankAccount
  @@id = 0

  def initialize( name )
    @id = @@id = (@@id + 1)
    @name = name
    @balance = 0
  end

  def deposit( amount )
    @balance += amount if amount > 0
  end

  def withdraw( amount )
    @balance = @balance - amount

  end

  def to_s
    "Account #@id - Balance: #@balance (#@name)"
  end
end


class InsufficientFundsError < BankAccount
  def initialize( id, balance, amount )

  end

  def to_s
     "Account #{@id} has insufficient funds ($#{@balance}) to allow the withdrawal of $#{amount}"
  end
end

class NegativeAmountError < BankAccount
  def initialize( action, id )

  end

  def to_s
  "You cannot [action] a negative amount for account [id]"
  end
end

和驱动程序文件：

require_relative "bankaccount" 

accounts = []

choice = 1

until choice == 5
    puts "1. Open A Account Account"
    puts "2. View you Accounts"
    puts "3. Make A Deposit"
    puts "4. Make A Withdrawal"
    puts "5. Exit The Peoples Champ Bank"

    print "What Business would you like to take care of today? Choose one: "
    choice = gets.to_i

    case choice

    when 1 ;
        if accounts.size < 6
            print "What will the name of this account be? "
            name = gets.chomp
            accounts.push( BankAccount.new name )
            puts "The Account has been created"
        else
            puts "You have exceeded the maximum number of accounts"
        end

    when 2 ;
        accounts.each_with_index {|a, i| puts "#{i}. #{a}"}
    when 3 ;
        begin
            print "What is the deposit amount? "
            amount = gets.to_i
            accounts.each_with_index {|a, i| puts "#{i}. #{a}"}
            print "Which account would like to depositing to? "
            accounts[ gets.to_i ].deposit( amount )
        rescue NegativeAmountError => e
            puts e.to_s
        end

    when 4 ;
        begin
            print "How much would you like to withdraw? "
            amount = gets.to_i
            accounts.each_with_index {|a, i| puts "#{i}. #{a}"}
            print "Which account would you like to withdraw from? "
            accounts[ gets.to_i ].withdraw( amount )
        rescue InsufficientFundsError => e
            puts e.to_s
        end
    end
end

Answer 1

您似乎已正确使用begin / rescue / end，但看起来您实际上并未检查错误情况并引发异常。

例如：

def withdraw(amount)
  if @balance - amount < 0
    raise InsufficientFundsError.new(@id, @balance, amount)
  end
  @balance = @balance - amount
end

此外，您的例外应该是Exception的子类：

class InsufficientFundsError << Exception

错误处理。当帐户持有时，尝试提取更多资金时显示错误

1 个答案: