robitabu:
In this case I'm going to use abort() in a preliminary stage of the coding.
It's already been explained to you that calling abort() under any circumstances in an Arduino sketch is a bad idea. If you want the sketch to chop itself off at the ankles, you could use the while(1); that Coding Badly showed you. Personally I think doing that just because of duff input is probably a cop-out, but if you can't be bothered to do anything more user-friendly then it's a legitimate way to halt your sketch. Calling abort() is not.