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

DWORD is not a C++ type, it’s defined in <windows.h>.

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.

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