An object that represents a special condition that interrupts the normal flow of program execution.
- iOS 2.0+
- macOS 10.0+
- tvOS 9.0+
- watchOS 2.0+
NSException to implement exception handling. An exception is a special condition that interrupts the normal flow of program execution. Each application can interrupt the program for different reasons. For example, one application might interpret saving a file in a directory that is write-protected as an exception. In this sense, the exception is equivalent to an error. Another application might interpret the user’s key-press (for example, Control-C) as an exception: an indication that a long-running process should be aborted.