Section 17.1. Throwing Exceptions

17.1 Throwing Exceptions

All exceptions will either be of type System.Exception or of types derived from System.Exception. The CLR System namespace includes a number of exception types that can be used by your program. These exception types include ArgumentNullException, InvalidCastException, and OverflowException, as well as many others. You can guess their use based on their name . For example, ArgumentNull exception is thrown when an argument to a method is null when that is not an expected (or acceptable) value.

The current chapter describes how to write your programs to catch and handle exceptions. This chapter will also show you how to use the properties of the Exception class to provide information to the user about what went wrong, and it will show you how to create and use your own custom exception types.