Windows Data Types

Windows Data Types

Windows Data Types

The data types supported by Microsoft® Windows® are used to define function return values, function and message parameters, and structure members. They define the size and meaning of these elements.

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.

Type	Definition
ATOM	Atom. For more information, see Atoms .
BOOL	Boolean variable (should be TRUE or FALSE).
BOOLEAN	Boolean variable (should be TRUE or FALSE).
BYTE	Byte (8 bits).
CALLBACK	Calling convention for callback functions.
CHAR	8-bit Windows (ANSI) character. For more information, see Character Sets Used By Fonts .
COLORREF	Red, green, blue (RGB) color value (32 bits). See COLORREF for information on this type.
CONST	Variable whose value is to remain constant during execution.
CRITICAL_SECTION	Critical-section object. For more information, see Critical Section Objects .
DWORD	32-bit unsigned integer.
DWORD_PTR	Unsigned long type for pointer precision. Use when casting a pointer to a long type to perform pointer arithmetic.
DWORD32	32-bit unsigned integer.
DWORD64	64-bit unsigned integer.
FLOAT	Floating-point variable.
HACCEL	Handle to an accelerator table .
HANDLE	Handle to an object.
HBITMAP	Handle to a bitmap .
HBRUSH	Handle to a brush .
HCONV	Handle to a dynamic data exchange (DDE) conversation.
HCONVLIST	Handle to a DDE conversation list.
HCURSOR	Handle to a cursor .
HDC	Handle to a device context (DC).
HDDEDATA	Handle to DDE data.
HDESK	Handle to a desktop .
HDROP	Handle to an internal drop structure.
HDWP	Handle to a deferred window position structure.
HENHMETAFILE	Handle to an enhanced metafile .
HFILE	Handle to a file opened by OpenFile , not CreateFile .
HFONT	Handle to a font .
HGDIOBJ	Handle to a GDI object.
HGLOBAL	Handle to a global memory block.
HHOOK	Handle to a hook .
HICON	Handle to an icon .
HIMAGELIST	Handle to an image list.
HIMC	Handle to input context.
HINSTANCE	Handle to an instance.
HKEY	Handle to a registry key.
HKL	Input locale identifier.
HLOCAL	Handle to a local memory block.
HMENU	Handle to a menu .
HMETAFILE	Handle to a metafile .
HMODULE	Handle to a module.
HMONITOR	Handle to a display monitor.
HPALETTE	Handle to a palette .
HPEN	Handle to a pen .
HRGN	Handle to a region .
HRSRC	Handle to a resource.
HSZ	Handle to a DDE string.
HWINSTA	Handle to a window station .
HWND	Handle to a window .
INT	32-bit signed integer.
INT _PTR	Signed integral type for pointer precision. Use when casting a pointer to an integer to perform pointer arithmetic.
INT32	32-bit signed integer.
INT64	64-bit signed integer.
LANGID	Language identifier. For more information, see Locales .
LCID	Locale identifier. For more information, see Locales .
LCTYPE	Locale information type. For a list, see Locale and Language Information
LONG	32-bit signed integer.
LONG_PTR	Signed long type for pointer precision. Use when casting a pointer to a long to perform pointer arithmetic.
LONG32	32-bit signed integer.
LONG64	64-bit signed integer.
LONGLONG	64-bit signed integer.
LPARAM	Message parameter.
LPBOOL	Pointer to a BOOL .
LPBYTE	Pointer to a BYTE .
LPCOLORREF	Pointer to a COLORREF value.
LPCRITICAL_SECTION	Pointer to a CRITICAL_SECTION .
LPCSTR	Pointer to a constant null-terminated string of 8-bit Windows (ANSI) characters. For more information, see Character Sets Used By Fonts .
LPCTSTR	An LPCWSTR if UNICODE is defined, an LPCSTR otherwise.
LPCVOID	Pointer to a constant of any type.
LPCWSTR	Pointer to a constant null-terminated string of 16-bit Unicode characters. For more information, see Character Sets Used By Fonts .
LPDWORD	Pointer to a DWORD .
LPHANDLE	Pointer to a HANDLE .
LPINT	Pointer to an INT .
LPLONG	Pointer to a LONG .
LPSTR	Pointer to a null-terminated string of 8-bit Windows (ANSI) characters. For more information, see Character Sets Used By Fonts .
LPTSTR	An LPWSTR if UNICODE is defined, an LPSTR otherwise.
LPVOID	Pointer to any type.
LPWORD	Pointer to a WORD .
LPWSTR	Pointer to a null-terminated string of 16-bit Unicode characters. For more information, see Character Sets Used By Fonts .
LRESULT	Signed result of message processing.
LUID	Locally unique identifier.
PBOOL	Pointer to a BOOL .
PBOOLEAN	Pointer to a BOOL .
PBYTE	Pointer to a BYTE .
PCHAR	Pointer to a CHAR .
PCRITICAL_SECTION	Pointer to a CRITICAL_SECTION .
PCSTR	Pointer to a constant null-terminated string of 8-bit Windows (ANSI) characters. For more information, see Character Sets Used By Fonts .
PCTSTR	A PCWSTR if UNICODE is defined, a PCSTR otherwise.
PCWCH	Pointer to a constant WCHAR .
PCWSTR	Pointer to a constant null-terminated string of 16-bit Unicode characters. For more information, see Character Sets Used By Fonts .
PDWORD	Pointer to a DWORD .
PFLOAT	Pointer to a FLOAT .
PHANDLE	Pointer to a HANDLE .
PHKEY	Pointer to an HKEY .
PINT	Pointer to an INT .
PLCID	Pointer to an LCID .
PLONG	Pointer to a LONG .
PLUID	Pointer to a LUID .
POINTER _32	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.
POINTER _64	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.
PSHORT	Pointer to a SHORT .
PSTR	Pointer to a null-terminated string of 8-bit Windows (ANSI) characters. For more information, see Character Sets Used By Fonts .
PTBYTE	Pointer to a TBYTE .
PTCHAR	Pointer to a TCHAR .
PTSTR	A PWSTR if UNICODE is defined, a PSTR otherwise.
PUCHAR	Pointer to a UCHAR .
PUINT	Pointer to a UINT .
PULONG	Pointer to a ULONG .
PUSHORT	Pointer to a USHORT .
PVOID	Pointer to any type.
PWCHAR	Pointer to a WCHAR .
PWORD	Pointer to a WORD .
PWSTR	Pointer to a null-terminated string of 16-bit Unicode characters. For more information, see Character Sets Used By Fonts .
REGSAM	Security access mask for registry key.
SC_HANDLE	Handle to a service control manager database. For more information, see SCM Handles .
SC_LOCK	Handle to a service control manager database lock. For more information, see SCM Handles .
SERVICE_STATUS_HANDLE	Handle to a service status value. For more information, see SCM Handles .
SHORT	Short integer (16 bits).
SIZE _T	The maximum number of bytes to which a pointer can point. Use for a count that must span the full range of a pointer.
SSIZE _T	Signed SIZE_T .
TBYTE	A WCHAR if UNICODE is defined, a CHAR otherwise.
TCHAR	A WCHAR if UNICODE is defined, a CHAR otherwise.
UCHAR	Unsigned CHAR .
UINT	Unsigned INT .
UINT _PTR	Unsigned INT_PTR .
UINT32	Unsigned INT32 .
UINT64	Unsigned INT64 .
ULONG	Unsigned LONG .
ULONG_PTR	Unsigned LONG_PTR .
ULONG32	Unsigned LONG32 .
ULONG64	Unsigned LONG64 .
ULONGLONG	64-bit unsigned integer.
UNSIGNED	Unsigned attribute.
USHORT	Unsigned SHORT .
VOID	Any type.
WCHAR	16-bit Unicode character. For more information, see Character Sets Used By Fonts .
WINAPI	Calling convention for system functions.
WORD	16-bit unsigned integer.
WPARAM	Message parameter.