Author: Joshua Taylor Version: 1.0.0
Automated Teller Machines (ATM) are very important tools in the modern banking world for performing convenient, simple transactions such as withdrawals and account balance inquiries. This program aims to simulate the behavior of an ATM as a way to demonstrate some basic concepts in C#, such as exception handling and unit testing.
The program should take in user choices and perform the chosen transactionns while preventing the user's account from overdrafting (falling below $0.00)
AutomatedTeller targets the .NET Core 2.0 platform. The .NET Core 2.0 SDK can be downloaded from the following URL for Windows, Linux, and macOS:
https://www.microsoft.com/net/download/
The dotnet CLI utility would then be used to build and run the application:
cd AutomatedTeller
dotnet build
dotnet run
Additionally, users can build, run, and perform unit testing using Visual Studio 2017 or greater by opening the solution file at the root of this repository.
AutomatedTeller uses C# and the .NET Core 2.0 platform. The business logic of the program is spread across three static methods within the Program class. A unit testing project has been included, AutomatedTellerTest, which uses the xUnit framework.
WithdrawFunds is a method which takes two 128-bit floating point parameters for the user's current account balance and the amount that the user wishes to withdraw. This method will not allow any withdrawals that would place the user into overdraft by throwing an InvalidOperationException. Attempting to withdrawal a negative amount of funds will throw an ArgumentOutOfRangeException (depositing funds should only be done through the DepositFunds method). Upon sucessful operation, the resulting account balance will be returned.
This method does not destructively modify any of its parameters; therefore, it is upon the caller to ensure that the new balance is propogated to the data model.
DepositFunds is a method which takes two 128-bit floating point parameters for the user's current account balance and the amount that the user wishes to deposit. Attempting to deposit a negative amount of funds will throw an ArgumentOutOfRangeException (withdrawing funds should only be done through the WithdrawFunds method). Upon successful operation, the resulting account balnace will be returned.
This operation is performed non-destructively; therefore, it is upon the caller to ensure that the new balance is propogated to the data model.
ViewBalance is used to convert a 128-bit floating point representation of an account balance to a string using the user's current locale settings. Some example outputs in the en-US locale are as follows:
ViewBalance(4.50M) -> "$4.50"
ViewBalance(0.3M) -> "$0.30"
ViewBalance(1337.42M) -> "$1,337.42"
AutomatedTeller's data model simply consists of a single, 128-bit floating point variable that is local to the Program.Main method. No data persistence is supported for this application.
AutomatedTeller uses a simple finite state machine to determine its desired operation. A menu is displayed to the console, and the user's input determines whether to present an interface to withdraw funds or to deposit funds. These two states make use of their respective business logic methods defined above and are used to update the data model.
Additionally, an option to simply display the user's account balance is available in addition to an option to terminate the session.
- 3.21.2018 Joshua Taylor - Initial release. All tests passing assuming en-US locale.