Mudanças entre as edições de "Avoid encodings: Hungarian Notation"

Edição atual tal como às 12h15min de 27 de janeiro de 2020

Java programmers don’t need type encoding. Objects are strongly typed, and editing environments have advanced such that they detect a type error long before you can run a compile! So nowadays HN and other forms of type encoding are simply impediments. They make it harder to change the name or type of a variable, function, or class. They make it harder to read the code. And they create the possibility that the encoding system will mislead the reader.

Examples of Hungarian Notation:

• lAccountNum : variable is a long integer ("l");
• arru8NumberList : variable is an array of unsigned 8-bit integers ("arru8");
• bReadLine(bPort,&arru8NumberList) : function with a byte-value return code.
• strName : Variable represents a string ("str") containing the name, but does not specify how that string is implemented.
• rwPosition : variable represents a row ("rw");
• usName : variable represents an unsafe string ("us"), which needs to be "sanitized" before it is used (e.g. see code injection and cross-site scripting for examples of attacks that can be caused by using raw user input)
• szName : variable is a zero-terminated string ("sz"); this was one of Simonyi's original suggested prefixes.
• pX is a pointer to another type X; this contains very little semantic information.
• d is a prefix meaning difference between two values; for instance, dY might represent a distance along the Y-axis of a graph, while a variable just called y might be an absolute position. This is entirely semantic in nature.
• sz is a null- or zero-terminated string. In C, this contains some semantic information because it is not clear whether a variable of type char* is a pointer to a single character, an array of characters or a zero-terminated string.
• w marks a variable that is a word. This contains essentially no semantic information at all, and would probably be considered Systems Hungarian.
• b marks a byte, which in contrast to w might have semantic information, because in C the only byte-sized data type is the char, so these are sometimes used to hold numeric values. This prefix might clear ambiguity between whether the variable is holding a value that should be treated as a character or a number.

Examples related to type:

• bBusy : boolean
• chInitial : char
• cApples : count of items
• dwLightYears : double word (Systems)
• fBusy : flag (or float)
• 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
• u16Identifier : unsigned 16-bit integer (Systems)
• u32Identifier : unsigned 32-bit integer (Systems)
• stTime : clock time structure
• fnFunction : function name

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