Naming conventions (ArcObjects .NET 10.4 SDK)

Here are some suggestions for a naming convention. These help identify the variables' usage and type and thus reduce coding errors. This is an abridged Hungarian notation:

[<scope>_]<type><name>

Prefix	Variable scope
m	Instance class members
c	Static class member (including constants)
g	Global static variable
<empty>	local variable or struct or public class member

<type>

Prefix	Data Type
b	Boolean
by	byte or unsigned char
cx/cy	short used as size
d	double
dw	DWORD, double word or unsigned long
f	float
fn	function
h	handle
i	int (integer)
ip	smart pointer
l	long
p	a pointer
s	string
sz	ASCIIZ null-terminated string
w	WORD unsigned int
x,y	short used a coordinates

<name> describes how the variable is used or what it contains. The <scope> and <type> portions should always be lowercase, and the <name> should use mixed case:

Variable Name	Description
m_hWnd	a handle to HWND
ipEnvelope	a smart pointer to a COM interface
m_pUnkOuter	a pointer to an object
c_isLoaded	a static class member
g_pWindowList	a global pointer to an object

Type Names

All type names (class, struct, enum, and typedef) begin with an uppercase letter and use mixed case for the rest of the name:

class Foo : public CObject { . . .};
struct Bar { . . .};
enum ShapeType { . . . };
typedef int* FooInt;

Typedefs for function pointers (callbacks) append Proc to the end of their names.

typedef void (*FooProgressProc)(int step);

Enumeration values all begin with a lowercase string that identifies the project; in the case of ArcObjects, this is esri, and each string occurs on a separate line:

typedef enum esriQuuxness
{
    esriQLow,
    esriQMedium,
    esriQHigh
} esriQuuxness;

Function Names

Name functions using the following conventions:

For simple accessor and mutator functions, use Get<Property> and Set<Property>:

int GetSize();
void SetSize(int size);

If the client is providing storage for the result, use Query<Property>:

void QuerySize(int& size);

For state functions, use Set<State>, and Is<State> or Can<State>:

bool IsFileDirty();
void SetFileDirty(bool dirty);
bool CanConnect();

Where the semantics of an operation are obvious from the types of arguments, leave type names out of the function names.

Instead of

AddDatabase(Database& db);

consider using

Add(Database& db);

Instead of

ConvertFoo2Bar(Foo* foo, Bar* bar);

consider using

Convert(Foo* foo, Bar* bar)

If a client relinquishes ownership of some data to an object, use Give<Property>. If an object relinquishes ownership of some data to a client, use Take<Property>:

void GiveGraphic(Graphic* graphic);
Graphic* TakeGraphic(int itemNum);

Use function overloading when a particular operation works with different argument types:

void Append(const CString& text);
void Append(int number);

Argument names

Use descriptive argument names in function declarations. The argument name should clearly indicate what purpose the argument serves:

bool Send(int messageID, const char* address, const char* message);