Since I, j, k, l are int by default, a variable named God would, by default, be a 'real' number - ie, floating point. You'd have to declare the variable God to be an integer in order for it to be taken that way. Yes, this is probably a good candidate for the most delayed response ever.

Yes, it started in FORTRAN and leads to the following joke: God is real unless declared integer At least now you have the context so you can see the humor :)

No, it's not part of Hungarian notation. Hungarian notation was a programming practice that prefixed variables with the type (for example, iLoopCounter, dSalary, etc). The m_ or just plain _ prefix is a method to be able to use a good name in the class and as parameters. class myClass { string _name; public bool myFunction(string name) { _name = name; } } as an example. I think the m_ came into play when class global variables were directly accessable as it made it easier to read (nameClass.m_name is easier than nameClass._name), but with the shift to treating local variables as private and providing accessors, the m_ isn't as necessary and using the _ prefix preserves the "good" names and makes it easier to translate code between languages that are/are not case sensitive.