что такое dword в c

Why in C++ do we use DWORD rather than unsigned int? [duplicate]

I’m not afraid to admit that I’m somewhat of a C++ newbie, so this might seem like a silly question but.

I see DWORD used all over the place in code examples. When I look up what a DWORD truly means, its apparently just an unsigned int (0 to 4,294,967,295). So my question then is, why do we have DWORD? What does it give us that the integral type ‘unsigned int’ does not? Does it have something to do with portability and machine differences?

4 Answers 4

Also note unsigned int does not necessary have the range 0 to 4,294,967,295. See here.

When MS-DOS and Windows 3.1 operated in 16-bit mode, an Intel 8086 word was 16 bits, a Microsoft WORD was 16 bits, a Microsoft DWORD was 32 bits, and a typical compiler’s unsigned int was 16 bits.

When Windows NT operated in 32-bit mode, an Intel 80386 word was 32 bits, a Microsoft WORD was 16 bits, a Microsoft DWORD was 32 bits, and a typical compiler’s unsigned int was 32 bits. The names WORD and DWORD were no longer self-descriptive but they preserved the functionality of Microsoft programs.

When Windows operates in 64-bit mode, an Intel word is 64 bits, a Microsoft WORD is 16 bits, a Microsoft DWORD is 32 bits, and a typical compiler’s unsigned int is 32 bits. The names WORD and DWORD are no longer self-descriptive, AND an unsigned int no longer conforms to the principle of least surprises, but they preserve the functionality of lots of programs.

I don’t think WORD or DWORD will ever change.

Источник

Что такое dword в c

Типы данных Windows

Типы данных, поддерживаемые Microsoft ® Windows ® используются для определения возвращаемых значений функциями, параметров функций и сообщений и членов структур. Они определяют размер и значение этих элементов.

Булева переменная (должна быть ИСТИНА (TRUE) или ЛОЖЬ (FALSE)). Этот тип объявлен в Windef.h как показано ниже:

Булева переменная (должна быть ИСТИНА (TRUE) или ЛОЖЬ (FALSE)). Этот тип объявлен в Winnt.h как показано ниже:

Байт (8 бит). Этот тип объявлен в Windef.h как показано ниже:

Соглашение о вызовах для функций повторного вызова. Этот тип объявлен в Windef.h как показано ниже:

Переменная, значение которой остается постоянным в ходе выполнения программы. Этот тип объявлен в Windef.h как показано ниже:

32-разрядное беззнаковое целое число. Этот тип объявлен в Windef.h как показано ниже:

DWORDLONG64-разрядное беззнаковое целое число. Этот тип объявлен в Winnt.h как показано ниже:

Тип беззнаковый дальний для точности указателя. Используется тогда, когда производится приведение указателя к дальнему типу, чтобы выполнить арифметические операции над указателями.( Также обычно используется для общих 32-разрядных параметров, которые были расширены до 64 битов в 64-разрядном Windows ).

Источник

Windows Data Types

The data types supported by Windows are used to define function return values, function and message parameters, and structure members. They define the size and meaning of these elements. For more information about the underlying C/C++ data types, see Data Type Ranges.

The following table contains the following types: character, integer, Boolean, pointer, and handle. The character, integer, and Boolean types are common to most C compilers. Most of the pointer-type names begin with a prefix of P or LP. Handles refer to a resource that has been loaded into memory.

For more information about handling 64-bit integers, see Large Integers.

A handle to an object.

This type is declared in WinNT.h as follows:

typedef PVOID HANDLE;

This type is declared in WinDef.h as follows:

typedef HANDLE HBITMAP;

This type is declared in WinDef.h as follows:

typedef HANDLE HBRUSH;

This type is declared in WinDef.h as follows:

typedef HANDLE HCOLORSPACE;

A handle to a dynamic data exchange (DDE) conversation.

This type is declared in Ddeml.h as follows:

typedef HANDLE HCONV;

A handle to a DDE conversation list.

This type is declared in Ddeml.h as follows:

typedef HANDLE HCONVLIST;

This type is declared in WinDef.h as follows:

typedef HICON HCURSOR;

This type is declared in WinDef.h as follows:

typedef HANDLE HDC;

A handle to DDE data.

This type is declared in Ddeml.h as follows:

typedef HANDLE HDDEDATA;

This type is declared in WinDef.h as follows:

typedef HANDLE HDESK;

A handle to an internal drop structure.

This type is declared in ShellApi.h as follows:

typedef HANDLE HDROP;

A handle to a deferred window position structure.

This type is declared in WinUser.h as follows:

typedef HANDLE HDWP;

This type is declared in WinDef.h as follows:

typedef HANDLE HENHMETAFILE;

This type is declared in WinDef.h as follows:

This type is declared in WinDef.h as follows:

typedef HANDLE HFONT;

A handle to a GDI object.

This type is declared in WinDef.h as follows:

typedef HANDLE HGDIOBJ;

A handle to a global memory block.

This type is declared in WinDef.h as follows:

typedef HANDLE HGLOBAL;

This type is declared in WinDef.h as follows:

typedef HANDLE HHOOK;

This type is declared in WinDef.h as follows:

typedef HANDLE HICON;

A handle to an instance. This is the base address of the module in memory.

HMODULE and HINSTANCE are the same today, but represented different things in 16-bit Windows.

This type is declared in WinDef.h as follows:

typedef HANDLE HINSTANCE;

A handle to a registry key.

This type is declared in WinDef.h as follows:

typedef HANDLE HKEY;

An input locale identifier.

This type is declared in WinDef.h as follows:

typedef HANDLE HKL;

A handle to a local memory block.

This type is declared in WinDef.h as follows:

typedef HANDLE HLOCAL;

This type is declared in WinDef.h as follows:

typedef HANDLE HMENU;

This type is declared in WinDef.h as follows:

typedef HANDLE HMETAFILE;

A handle to a module. The is the base address of the module in memory.

HMODULE and HINSTANCE are the same in current versions of Windows, but represented different things in 16-bit Windows.

This type is declared in WinDef.h as follows:

typedef HINSTANCE HMODULE;

A handle to a display monitor.

This type is declared in WinDef.h as follows:

if(WINVER >= 0x0500) typedef HANDLE HMONITOR;

A handle to a palette.

This type is declared in WinDef.h as follows:

typedef HANDLE HPALETTE;

This type is declared in WinDef.h as follows:

typedef HANDLE HPEN;

The return codes used by COM interfaces. For more information, see Structure of the COM Error Codes. To test an HRESULT value, use the FAILED and SUCCEEDED macros.

This type is declared in WinNT.h as follows:

typedef LONG HRESULT;

This type is declared in WinDef.h as follows:

typedef HANDLE HRGN;

A handle to a resource.

This type is declared in WinDef.h as follows:

typedef HANDLE HRSRC;

A handle to a DDE string.

This type is declared in Ddeml.h as follows:

typedef HANDLE HSZ;

This type is declared in WinDef.h as follows:

typedef HANDLE WINSTA;

This type is declared in WinDef.h as follows:

typedef HANDLE HWND;

This type is declared in WinDef.h as follows:

A signed integer type for pointer precision. Use when casting a pointer to an integer to perform pointer arithmetic.

This type is declared in BaseTsd.h as follows:

An 8-bit signed integer.

This type is declared in BaseTsd.h as follows:

typedef signed char INT8;

A 16-bit signed integer.

This type is declared in BaseTsd.h as follows:

typedef signed short INT16;

This type is declared in BaseTsd.h as follows:

typedef signed int INT32;

This type is declared in BaseTsd.h as follows:

typedef signed __int64 INT64;

A language identifier. For more information, see Language Identifiers.

This type is declared in WinNT.h as follows:

typedef WORD LANGID;

A locale identifier. For more information, see Locale Identifiers.

This type is declared in WinNT.h as follows:

typedef DWORD LCID;

A locale information type. For a list, see Locale Information Constants.

This type is declared in WinNls.h as follows:

typedef DWORD LCTYPE;

This type is declared in WinNls.h as follows:

typedef DWORD LGRPID;

This type is declared in WinNT.h as follows:

This type is declared in WinNT.h as follows:

A signed long type for pointer precision. Use when casting a pointer to a long to perform pointer arithmetic.

This type is declared in BaseTsd.h as follows:

This type is declared in BaseTsd.h as follows:

typedef signed int LONG32;

This type is declared in BaseTsd.h as follows:

typedef __int64 LONG64;

A message parameter.

This type is declared in WinDef.h as follows:

typedef LONG_PTR LPARAM;

This type is declared in WinDef.h as follows:

typedef BOOL far *LPBOOL;

This type is declared in WinDef.h as follows:

typedef BYTE far *LPBYTE;

This type is declared in WinDef.h as follows:

typedef DWORD *LPCOLORREF;

A pointer to a constant null-terminated string of 8-bit Windows (ANSI) characters. For more information, see Character Sets Used By Fonts.

This type is declared in WinNT.h as follows:

typedef __nullterminated CONST CHAR *LPCSTR;

An LPCWSTR if UNICODE is defined, an LPCSTR otherwise. For more information, see Windows Data Types for Strings.

This type is declared in WinNT.h as follows:

A pointer to a constant of any type.

This type is declared in WinDef.h as follows:

typedef CONST void *LPCVOID;

A pointer to a constant null-terminated string of 16-bit Unicode characters. For more information, see Character Sets Used By Fonts.

This type is declared in WinNT.h as follows:

typedef CONST WCHAR *LPCWSTR;

This type is declared in WinDef.h as follows:

typedef DWORD *LPDWORD;

This type is declared in WinDef.h as follows:

typedef HANDLE *LPHANDLE;

This type is declared in WinDef.h as follows:

This type is declared in WinDef.h as follows:

typedef long *LPLONG;

A pointer to a null-terminated string of 8-bit Windows (ANSI) characters. For more information, see Character Sets Used By Fonts.

This type is declared in WinNT.h as follows:

typedef CHAR *LPSTR;

An LPWSTR if UNICODE is defined, an LPSTR otherwise. For more information, see Windows Data Types for Strings.

This type is declared in WinNT.h as follows:

A pointer to any type.

This type is declared in WinDef.h as follows:

typedef void *LPVOID;

This type is declared in WinDef.h as follows:

typedef WORD *LPWORD;

A pointer to a null-terminated string of 16-bit Unicode characters. For more information, see Character Sets Used By Fonts.

This type is declared in WinNT.h as follows:

typedef WCHAR *LPWSTR;

Signed result of message processing.

This type is declared in WinDef.h as follows:

typedef LONG_PTR LRESULT;

This type is declared in WinDef.h as follows:

typedef BOOL *PBOOL;

This type is declared in WinNT.h as follows:

typedef BOOLEAN *PBOOLEAN;

This type is declared in WinDef.h as follows:

typedef BYTE *PBYTE;

This type is declared in WinNT.h as follows:

typedef CHAR *PCHAR;

A pointer to a constant null-terminated string of 8-bit Windows (ANSI) characters. For more information, see Character Sets Used By Fonts.

This type is declared in WinNT.h as follows:

typedef CONST CHAR *PCSTR;

A PCWSTR if UNICODE is defined, a PCSTR otherwise. For more information, see Windows Data Types for Strings.

This type is declared in WinNT.h as follows:

A pointer to a constant null-terminated string of 16-bit Unicode characters. For more information, see Character Sets Used By Fonts.

This type is declared in WinNT.h as follows:

typedef CONST WCHAR *PCWSTR;

This type is declared in WinDef.h as follows:

typedef DWORD *PDWORD;

This type is declared in WinNT.h as follows:

typedef DWORDLONG *PDWORDLONG;

This type is declared in BaseTsd.h as follows:

typedef DWORD_PTR *PDWORD_PTR;

This type is declared in BaseTsd.h as follows:

typedef DWORD32 *PDWORD32;

This type is declared in BaseTsd.h as follows:

typedef DWORD64 *PDWORD64;

This type is declared in WinDef.h as follows:

typedef FLOAT *PFLOAT;

This type is declared in BaseTsd.h as follows:

This type is declared in WinNT.h as follows:

typedef HANDLE *PHANDLE;

This type is declared in WinDef.h as follows:

typedef HKEY *PHKEY;

This type is declared in WinDef.h as follows:

This type is declared in BaseTsd.h as follows:

typedef INT_PTR *PINT_PTR;

This type is declared in BaseTsd.h as follows:

typedef INT8 *PINT8;

This type is declared in BaseTsd.h as follows:

typedef INT16 *PINT16;

This type is declared in BaseTsd.h as follows:

typedef INT32 *PINT32;

This type is declared in BaseTsd.h as follows:

typedef INT64 *PINT64;

This type is declared in WinNT.h as follows:

typedef PDWORD PLCID;

This type is declared in WinNT.h as follows:

typedef LONG *PLONG;

This type is declared in WinNT.h as follows:

typedef LONGLONG *PLONGLONG;

This type is declared in BaseTsd.h as follows:

typedef LONG_PTR *PLONG_PTR;

This type is declared in BaseTsd.h as follows:

typedef LONG32 *PLONG32;

This type is declared in BaseTsd.h as follows:

typedef LONG64 *PLONG64;

A 32-bit pointer. On a 32-bit system, this is a native pointer. On a 64-bit system, this is a truncated 64-bit pointer.

This type is declared in BaseTsd.h as follows:

A 64-bit pointer. On a 64-bit system, this is a native pointer. On a 32-bit system, this is a sign-extended 32-bit pointer.

Note that it is not safe to assume the state of the high pointer bit.

This type is declared in BaseTsd.h as follows:

This type is declared in BaseTsd.h as follows:

#define POINTER_SIGNED __sptr

An unsigned pointer.

This type is declared in BaseTsd.h as follows:

#define POINTER_UNSIGNED __uptr

This type is declared in WinNT.h as follows:

typedef SHORT *PSHORT;

This type is declared in BaseTsd.h as follows:

typedef SIZE_T *PSIZE_T;

This type is declared in BaseTsd.h as follows:

typedef SSIZE_T *PSSIZE_T;

A pointer to a null-terminated string of 8-bit Windows (ANSI) characters. For more information, see Character Sets Used By Fonts.

This type is declared in WinNT.h as follows:

This type is declared in WinNT.h as follows:

typedef TBYTE *PTBYTE;

This type is declared in WinNT.h as follows:

typedef TCHAR *PTCHAR;

A PWSTR if UNICODE is defined, a PSTR otherwise. For more information, see Windows Data Types for Strings.

This type is declared in WinNT.h as follows:

This type is declared in WinDef.h as follows:

typedef UCHAR *PUCHAR;

This type is declared in BaseTsd.h as follows:

This type is declared in WinDef.h as follows:

typedef UINT *PUINT;

This type is declared in BaseTsd.h as follows:

typedef UINT_PTR *PUINT_PTR;

This type is declared in BaseTsd.h as follows:

typedef UINT8 *PUINT8;

This type is declared in BaseTsd.h as follows:

typedef UINT16 *PUINT16;

This type is declared in BaseTsd.h as follows:

typedef UINT32 *PUINT32;

This type is declared in BaseTsd.h as follows:

typedef UINT64 *PUINT64;

This type is declared in WinDef.h as follows:

typedef ULONG *PULONG;

This type is declared in WinDef.h as follows:

typedef ULONGLONG *PULONGLONG;

This type is declared in BaseTsd.h as follows:

typedef ULONG_PTR *PULONG_PTR;

This type is declared in BaseTsd.h as follows:

typedef ULONG32 *PULONG32;

This type is declared in BaseTsd.h as follows:

typedef ULONG64 *PULONG64;

This type is declared in WinDef.h as follows:

typedef USHORT *PUSHORT;

A pointer to any type.

This type is declared in WinNT.h as follows:

typedef void *PVOID;

This type is declared in WinNT.h as follows:

typedef WCHAR *PWCHAR;

This type is declared in WinDef.h as follows:

typedef WORD *PWORD;

A pointer to a null-terminated string of 16-bit Unicode characters. For more information, see Character Sets Used By Fonts.

This type is declared in WinNT.h as follows:

typedef WCHAR *PWSTR;

A 64-bit unsigned integer.

This type is declared as follows:

typedef unsigned __int64 QWORD;

A handle to a service control manager database. For more information, see SCM Handles.

This type is declared in WinSvc.h as follows:

typedef HANDLE SC_HANDLE;

A lock to a service control manager database. For more information, see SCM Handles.

This type is declared in WinSvc.h as follows:

typedef LPVOID SC_LOCK;

A handle to a service status value. For more information, see SCM Handles.

This type is declared in WinSvc.h as follows:

typedef HANDLE SERVICE_STATUS_HANDLE;

This type is declared in WinNT.h as follows:

typedef short SHORT;

The maximum number of bytes to which a pointer can point. Use for a count that must span the full range of a pointer.

This type is declared in BaseTsd.h as follows:

typedef ULONG_PTR SIZE_T;

This type is declared in BaseTsd.h as follows:

typedef LONG_PTR SSIZE_T;

A WCHAR if UNICODE is defined, a CHAR otherwise.

This type is declared in WinNT.h as follows:

A WCHAR if UNICODE is defined, a CHAR otherwise.

This type is declared in WinNT.h as follows:

This type is declared in WinDef.h as follows:

typedef unsigned char UCHAR;

An unsigned HALF_PTR. Use within a structure that contains a pointer and two small fields.

This type is declared in BaseTsd.h as follows:

An unsigned INT. The range is 0 through 4294967295 decimal.

This type is declared in WinDef.h as follows:

typedef unsigned int UINT;

This type is declared in BaseTsd.h as follows:

This type is declared in BaseTsd.h as follows:

typedef unsigned char UINT8;

This type is declared in BaseTsd.h as follows:

typedef unsigned short UINT16;

An unsigned INT32. The range is 0 through 4294967295 decimal.

This type is declared in BaseTsd.h as follows:

typedef unsigned int UINT32;

An unsigned INT64. The range is 0 through 18446744073709551615 decimal.

This type is declared in BaseTsd.h as follows:

typedef usigned __int 64 UINT64;

An unsigned LONG. The range is 0 through 4294967295 decimal.

This type is declared in WinDef.h as follows:

typedef unsigned long ULONG;

A 64-bit unsigned integer. The range is 0 through 18446744073709551615 decimal.

This type is declared in WinNT.h as follows:

This type is declared in BaseTsd.h as follows:

An unsigned LONG32. The range is 0 through 4294967295 decimal.

This type is declared in BaseTsd.h as follows:

typedef unsigned int ULONG32;

An unsigned LONG64. The range is 0 through 18446744073709551615 decimal.

This type is declared in BaseTsd.h as follows:

typedef unsigned __int64 ULONG64;

This type is declared in Winternl.h as follows:

An unsigned SHORT. The range is 0 through 65535 decimal.

This type is declared in WinDef.h as follows:

typedef unsigned short USHORT;

An update sequence number (USN).

This type is declared in WinNT.h as follows:

typedef LONGLONG USN;

This type is declared in WinNT.h as follows:

A 16-bit Unicode character. For more information, see Character Sets Used By Fonts.

This type is declared in WinNT.h as follows:

typedef wchar_t WCHAR;

The calling convention for system functions.

This type is declared in WinDef.h as follows:

#define WINAPI __stdcall

CALLBACK, WINAPI, and APIENTRY are all used to define functions with the __stdcall calling convention. Most functions in the Windows API are declared using WINAPI. You may wish to use CALLBACK for the callback functions that you implement to help identify the function as a callback function.

A 16-bit unsigned integer. The range is 0 through 65535 decimal.

This type is declared in WinDef.h as follows:

typedef unsigned short WORD;

A message parameter.

This type is declared in WinDef.h as follows:

Источник

• ← что такое pnl в маркетинге
• в какой папке хранятся миры майнкрафт →

Data type	Description
APIENTRY	The calling convention for system functions. This type is declared in WinDef.h as follows: #define APIENTRY WINAPI
ATOM	An atom. For more information, see About Atom Tables. This type is declared in WinDef.h as follows: typedef WORD ATOM;
BOOL	A Boolean variable (should be TRUE or FALSE). This type is declared in WinDef.h as follows: typedef int BOOL;
BOOLEAN	A Boolean variable (should be TRUE or FALSE). This type is declared in WinNT.h as follows: typedef BYTE BOOLEAN;
BYTE	A byte (8 bits). This type is declared in WinDef.h as follows: typedef unsigned char BYTE;
CALLBACK	The calling convention for callback functions. This type is declared in WinDef.h as follows: #define CALLBACK __stdcall CALLBACK, WINAPI, and APIENTRY are all used to define functions with the __stdcall calling convention. Most functions in the Windows API are declared using WINAPI. You may wish to use CALLBACK for the callback functions that you implement to help identify the function as a callback function.
CCHAR	An 8-bit Windows (ANSI) character. This type is declared in WinNT.h as follows: typedef char CCHAR;
CHAR	An 8-bit Windows (ANSI) character. For more information, see Character Sets Used By Fonts. This type is declared in WinNT.h as follows: typedef char CHAR;
COLORREF	The red, green, blue (RGB) color value (32 bits). See COLORREF for information on this type. This type is declared in WinDef.h as follows: typedef DWORD COLORREF;
CONST	A variable whose value is to remain constant during execution. This type is declared in WinDef.h as follows: #define CONST const
DWORD	A 32-bit unsigned integer. The range is 0 through 4294967295 decimal. This type is declared in IntSafe.h as follows: typedef unsigned long DWORD;
DWORDLONG	A 64-bit unsigned integer. The range is 0 through 18446744073709551615 decimal. This type is declared in IntSafe.h as follows: typedef unsigned __int64 DWORDLONG;
DWORD_PTR	An unsigned long type for pointer precision. Use when casting a pointer to a long type to perform pointer arithmetic. (Also commonly used for general 32-bit parameters that have been extended to 64 bits in 64-bit Windows.) This type is declared in BaseTsd.h as follows: typedef ULONG_PTR DWORD_PTR;
DWORD32	A 32-bit unsigned integer. This type is declared in BaseTsd.h as follows: typedef unsigned int DWORD32;
DWORD64	A 64-bit unsigned integer. This type is declared in BaseTsd.h as follows: typedef unsigned __int64 DWORD64;
FLOAT	A floating-point variable. This type is declared in WinDef.h as follows: typedef float FLOAT;
HACCEL	A handle to an accelerator table. This type is declared in WinDef.h as follows: typedef HANDLE HACCEL;
HALF_PTR	Half the size of a pointer. Use within a structure that contains a pointer and two small fields. This type is declared in BaseTsd.h as follows: C++
HANDLE