# exception

Source: https://ref.dm-lang.org/exception
Added in BYOND 508.

### Vars
- name: A text string (such as an error message) or other value
- file: The filename where the error occurred, if debugging info is present
- line: The line where the error occurred, if debugging info is present
- desc: Detailed error info including call stack, only used when sent to world.Error()


This datum is created automatically when a runtime error is encountered, **if** it happens within a try/catch block or you have defined a global error handler with `world.Error()`. (The New() proc is not called when this happens.) This provides a convenient package for getting file and line number info associated with an error.

If you throw your own exceptions, you do not have to use this, but the `EXCEPTION` macro is provided to easily create one with the current file and line number.

The `desc` value is only filled in when you have a world.Error() handler and there is no try/catch handling this error. Just like when no handler is present, less detail will be provided after multiple runtime errors have occurred. This only exists as a convenience feature for logging errors if you want to use something other than world.log.

### See also
- [try and catch statements](https://ref.dm-lang.org/proc/try.md)
- [Error proc (world)](https://ref.dm-lang.org/world/proc/Error.md)
- [throw statement](https://ref.dm-lang.org/proc/throw.md)
- [EXCEPTION proc](https://ref.dm-lang.org/proc/EXCEPTION.md)
- [caller var (proc)](https://ref.dm-lang.org/proc/var/caller.md)
- [stddef.dm file](https://ref.dm-lang.org/appendix/stddefdotdm.md)