Hungarian Notation - Examples

Examples

• bBusy : boolean
• chInitial : char
• cApples : count of items
• dwLightYears : double word (Systems)
• fBusy : boolean (flag)
• nSize : integer (Systems) or count (Apps)
• iSize : integer (Systems) or index (Apps)
• fpPrice: floating-point
• dbPi : double (Systems)
• pFoo : pointer
• rgStudents : array, or range
• szLastName : zero-terminated string
• u32Identifier : unsigned 32-bit integer (Systems)
• stTime : clock time structure
• fnFunction : function name

The mnemonics for pointers and arrays, which are not actual data types, are usually followed by the type of the data element itself:

• pszOwner : pointer to zero-terminated string
• rgfpBalances : array of floating-point values
• aulColors : array of unsigned long (Systems)

While Hungarian notation can be applied to any programming language and environment, it was widely adopted by Microsoft for use with the C language, in particular for Microsoft Windows, and its use remains largely confined to that area. In particular, use of Hungarian notation was widely evangelized by Charles Petzold's "Programming Windows", the original (and for many readers, the definitive) book on Windows API programming. Thus, many commonly seen constructs of Hungarian notation are specific to Windows:

• For programmers who learned Windows programming in C, probably the most memorable examples are the wParam (word-size parameter) and lParam (long-integer parameter) for the WindowProc function.
• hwndFoo : handle to a window
• lpszBar : long pointer to a zero-terminated string

The notation is sometimes extended in C++ to include the scope of a variable, separated by an underscore. This extension is often also used without the Hungarian type-specification:

• g_nWheels : member of a global namespace, integer
• m_nWheels : member of a structure/class, integer
• m_wheels, _wheels : member of a structure/class
• s_wheels : static member of a class
• c_wheels : static member of a function