When should one use Environment.Exit to terminate a console application?

The only reason for calling Exit() as the last line of the Main method is if there might be other foreground threads running. They would stay running if execution just fell off the end of Main. Even in this case, it would usually be a better idea either to put in some explicit graceful termination into the other threads - or make them background threads to start with.

If you ever want to return a different exit code from Main, the simpler way to achieve that is to declare it to return int.

In short, I don't think you need Environment.Exit() here, and it's worth asking your colleagues exactly why they're using it - chances are they won't be able to give you a good reason, and it's another bit of fluff you can cut out.

This is (compatibility) for command-line programs to indicate success or failure to an underlying shell, and is inherited from older C-style main loops where the prototype of the main function was

int main(void);

int main(int argc, char *argv[]);

The return value of 0 traditionally meant success, while non-zero meant failure or something else, depending on what the programmer decided.

References

• Wikipedia for more information on the main function.

• MSDN documentation on Environment.Exit()

Basically, the statement Environment.Exit(0) tells the operating system that this is a "clean" exit. There are other numbers as well, each with a different meaning like, Environment.Exit(1).

However, one thing to note is that the "Main" has been declared as returning nothing "void", so the exit code will really not have a meaning to it.

Just in case you wanted to know more about the different exit codes, have a look here:

System Error Codes (0-499)