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

Data Types

Value

Meaning

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. (Also commonly used for general 32-bit parameters that have been extended to 64 bits in 64-bit Windows. )

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. The value is the base address of the 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 LPCTSTR 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

PWSTR if UNICODE is defined, a PSTR otherwise.

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.