Hungarian Notation

A linguistic convention requiring one

or more letters to be added to the front of {variable} names

to denote {scope} and/or {type}.

Hungarian Notation is mainly confined to {Microsoft Windows}

programming environments, such as Microsoft {C}, {C::} and

{Visual Basic}.

It was originally devised by {Charles Simonyi}, a Hungarian,

who was a senior programmer at {Microsoft} for many years. He

disliked the way that names in C programs could stand for any

kind of variable. This was for ever leading to mistakes, as

programmers tried to manipulate variables in ways that their

type prohibited, which they would never had done if they

remembered what sort they were.

According to legend, fellow programmers at Microsoft looked at

the convoluted, vowel-less variable names produced by his

scheme and, like everyone else who has come into contact with

them since, said something like "This might as well be in

Greek - or even Hungarian!". They almost certainly had in mind

as well another kind of {mathematical} system called "Polish

notation" (a variant form called {reverse Polish notation} is

commonly used in {calculators}, which leads to expressions

without brackets or punctuation which are easier to enter).

They put the two together and made up the name "Hungarian

notation".

Hungarian Notation is not really necessary when using a modern

{strongly-typed language} as the {compiler} warns the

programmer if a variable of one type is used as if it were

another type. It is less useful in {object-oriented

programming} languages such as {C::}, where many variables are

going to be instances of {classes} [Why?].

In addition, variable names are essentially only {comments},

and thus are just as susceptible to becoming out of date and

incorrect as any other comment. For example, if a {signed}

{short} {int} becomes an unsigned {long} int, the variable

name, and every use of it throughout the program, should be

changed to reflect its new type.

If used appropriately however, it does enforce a certain

consistency, especially when scoping is taken into account

as well as type (for example g_ for global variables,

m_ for members, c_ for static members, l_ for local, etc.).

{Simonyi's original monograph

(http://www.strangecreations.com/library/c/naming.txt)}.

{Microsoft VB Naming Conventions

(http://support.microsoft.com/support/kb/articles/Q110/2/64.asp)}.

(1999-06-03)