Guide to Win32 API Data Type Naming Conventions

Question

I'm new to programming with the Win32 API, and I'm still getting used to the prefix / suffix data type naming conventions. While Google and a little common sense will normally explain what the prefix is referring to, it would be nice if there was one (relatively) concise guide to explain them. Does anyone know of a resource like this?

And on a related note, what does the '_' (underscore) prefix mean with a variable? Does that underscore have a name, other than "underscore"?

Answer 1

Win32 API follows Hungarian Notation

Answer 2

It's called a hungarian notation, Wikipedia has some information about it, and there's something on MSDN.

Answer 3

The naming convention is called Hungarian Notation, as mentioned by others. Since you're not familiar with it, and are probably going to start using it, it is worth mentioning there are two main flavors of Hungarian:

1. prefix the variable with its type code
2. prefix the variable with its usage code

The difference is visible when, for instance, an int is used to describe the number of bytes in a certain strings. On the former, nLen will be used, meaning the variable is an int. On the later, cbLen will be used, meaning the variable counts bytes (as opposed to cchLen, which counts characters). Give this article a look, should give you a better explanation.

As for the underscores in front of a variable or function - this is a naming convention reserved for the compiler and its standard library. Some people use it for other purposes, but they really shouldn't. The purpose of the convention is to provide the compiler a naming standard that will prevent collisions with names given by the user.