DWORD

Unsigned 32-bit integer typedef unsigned long DWORD;

Description

A 32-bit unsigned integer. This data type is defined in WinDef.h.

The DWORD type is a fundamental data type used throughout the Windows API to represent unsigned integer values that are 32 bits in size.

Definition

<syntaxhighlight lang="c++">
typedef unsigned long DWORD;
</syntaxhighlight>

Remarks

DWORD is commonly used for:

• Bit flags: For manipulating individual bits within a 32-bit value.
• Counters and sizes: Representing counts or memory sizes up to 2³² - 1.
• Return values: Many functions return a DWORD to indicate status or results.
• Data buffers: Allocating and managing blocks of memory.

On systems where long is 64 bits (e.g., some Unix-like systems), the size of DWORD might not be 32 bits as expected. However, on Windows, long is typically 32 bits, making DWORD consistently a 32-bit unsigned integer.

For guaranteed 32-bit unsigned integer behavior across different platforms or compiler settings, you might consider using uint32_t from the C++ <cstdint> header.

Example Usage

The following snippet demonstrates setting a bit flag using a DWORD:

<syntaxhighlight lang="c++">
#include <windows.h>

void SetBitFlag(DWORD* flags, DWORD flagToSet) {
    *flags |= flagToSet; // Use bitwise OR to set the flag
}

int main() {
    DWORD myFlags = 0;
    DWORD SPECIFIC_FLAG = 0x00000001; // Example flag

    SetBitFlag(&myFlags, SPECIFIC_FLAG);

    if (myFlags & SPECIFIC_FLAG) {
        // The flag is set
    }

    return 0;
}
</syntaxhighlight>

See Also