Why in C do we use DWORD rather than unsigned int

Question

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

User · Answer

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

User · Answer

For myself  I would assume unsigned int is platform specific  Integer could be 8 bits  16 bits  32 bits or even 64 bits   DWORD in the other hand  specifies its own size  which is Double Word  Word are 16 bits so DWORD will be known as 32 bit across all platform

User · Answer

SDK developers prefer to define their own types using typedef  This allows changing underlying types only in one place  without changing all client code  It is important to follow this convention  DWORD is unlikely to be changed  but types like DWORD PTR are different on different platforms  like Win32 and x64  So  if some function has DWORD parameter  use DWORD and not unsigned int  and your code will be compiled in all future windows headers versions

User · Answer

DWORD is not a C   type  it s defined in  lt windows h gt    The reason is that DWORD has a specific range and format Windows functions rely on  so if you require that specific range use that type   Or as they say  When in Rome  do as the Romans do    For you  that happens to correspond to unsigned int  but that might not always be the case  To be safe  use DWORD when a DWORD is expected  regardless of what it may actually be   For example  if they ever changed the range or format of unsigned int they could use a different type to underly DWORD to keep the same requirements  and all code using DWORD would be none-the-wiser   Likewise  they could decide DWORD needs to be unsigned long long  change it  and all code using DWORD would be none-the-wiser      Also note unsigned int does not necessary have the range 0 to 4 294 967 295  See here

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

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