If a program behaves abnormally, encounters an unexpected input, or detects an anomaly in its operation, it must react to such an event. This is called exception handling.

A type of error handling that allows control and information to be passed to an exception handler when an exception occurs. try blocks, catch blocks, and throw expressions are the constructs used to implement formal exception handling in C++.

A type of error handling that allows control and information to be passed to an exception handler when an exception occurs. Under the OS/2 operating system, exceptions are generated by the system and handled by user code. In the C++ language, try, catch, and throw expressions are the constructs used to implement C++ exception handling. See structured exception handling.

An event that occurs as a program runs and that requires software outside the normal flow of control to be run.