This course introduces methods and describes how to define and use them in object-oriented languages such as C#. Methods enable you to divide your solutions into logical components that can even be reused in other applications. Methods may require exceptions to be used to indicate an error condition to the code that calls your methods. An understanding of exception handling can help you develop error-free applications. The ability to access and manipulate the files on the file system is a common requirement for many applications. An understanding of how to read and write to files by using the classes in Microsoft® .NET Framework is important for developing applications that can access and manipulate data stored outside of the applications.