Are variable prefixes (“Hungarian notation”) really necessary anymore? [closed]

Answer 1

If Hungarian means "prefix with a type abbreviation" such as uCount or pchzName, then I would say this practice is bad and thankfully seems to be fading from common use.

However, I do still think that prefixes are very useful for scope. At my studio we use this convention for prefixing variables :

i_  // input-only function parameter (most are these)
o_  // output-only function parameter (so a non-const & or * type)
io_ // bidirectional func param
_   // private member var (c#)
m_  // private member var (c++)
s_  // static member var (c++)
g_  // global (rare, typically a singleton accessor macro)

I've found this to be very useful. The func param prefixes in particular are useful. Way down inside a function you can always tell where that var came from at a glance. And typically we will copy the var to another when we want to modify it or change its meaning.

So in short: prefixes for types are unnecessary with modern tools. The IDE takes care of identifying and checking that stuff for you. But scope-based prefixes are very useful for readability and clarity.

There are also fun side benefits like with Intellisense. You can type i_ ctrl-space and get all the input params to the func to choose from. Or g_ ctrl-space to get all your singletons. It's a time-saver.

Answer 2

I always prefix instance member variables with m__ and static member variables with s_. I've come across variable articles from MS people who recommend/discourage the approach.

I'm also pretty sure I've come across the m_ prefix when looking through the standard .NET libraries using Reflector...

Answer 3

No, we don't need them. I used to follow this when back in the days, we were forced to follow that kind of a coding standard.

Also with Intellisense, Code Definition Window and Refactoring tools built into VS and other third party plugins like CodeRush express and Refactor Pro, it's easier to work with code without it.

Answer 4

Well, to counter, I'd say - it depends. I'm personally against them, but it comes down to your team. Each team should be responsible for developing their own set of guidelines. Hopefully that doesn't include so-called Hungarian Notation, but it really should be a team decision. You might find cases where you want to break with the style guidelines.

Answer 5

I use it all the time but that could because I use VBA with Access and Excel.

For me CountAll is a name intCountAll is a name with this difference that it additionially describes the name (never intended for machines just for humans) like sintCountAll tells me its static pintCountAll private and gintCountAll global so for the purpose I use it; it is very usefull.

• control names is a time safer like instead of ControlName I have lblControlName, txtControlName, cboControlName, lstControlName etc so when I use VBA I just type lst and I have all the names I need so I don't have to remember what is the exact name which saves me a lot of time but again this is mainly VBA in Access and Excel.

Regards Emil

Answer 6

I sometimes use a kind of prefix where pName is a parameter passed into my function (notice I don't prefix the type), oName is local to my current method, mName is a member to the class I'm in and cName is a constant or static readonly member.

Personally I find it helps.