Ruby

Encapsulation

class BankAccount
  def initialize(account_number, balance)
    @account_number = account_number
    @balance = balance
  end

  def display_balance
    puts "Account Number: #{@account_number}"
    puts "Balance: $#{@balance}"
  end

  protected

  private

end

class SavingsAccount < BankAccount
end

account = SavingsAccount.new("123456789", 5000)
account.display_balance
account.withdraw(500)
account.display_balance


class BankAccount
  def initialize(account_number, balance)
    @account_number = account_number
    @balance = balance
  end

  def display_balance
    puts "Account Number: #{@account_number}"
    puts "Balance: $#{@balance}"
  end

  protected

    def withdraw(amount)
      @balance -= amount if sufficient_funds?(amount)
    end

  private

    def sufficient_funds?(amount)
      amount <= @balance
    end
end

class SavingsAccount < BankAccount
  def withdraw(amount)
    super(amount) if amount <= 1000
  end
end

account = SavingsAccount.new("123456789", 5000)
account.display_balance
account.withdraw(500)
account.display_balance
