pPropertyCount

pPropertyCount is a naming convention used in C and C++ code, particularly in Windows API and COM-style interfaces, to denote a pointer to a count of properties. The leading p signals that the object is a pointer, while PropertyCount describes the data being pointed to. The pointed-to type is typically an unsigned integer, such as DWORD*, UINT*, or size_t*, and the value represents how many properties are present, returned, or available in a collection or property set.

Usage patterns often treat pPropertyCount as an output parameter. A common two-step approach involves first passing a pointer to a count variable (often initialized to zero) to query the required size, then allocating memory for that many properties and calling the function again to retrieve the data, with the function updating the count to reflect the actual number retrieved.

Contexts where pPropertyCount appears include enumerating properties in a property store, retrieving a list of properties from a storage or interface, or reporting the size of a property array. The exact type and semantics depend on the API; pPropertyCount simply holds the number of properties as reported by the call, not the number of bytes.

Considerations when using pPropertyCount include ensuring proper memory allocation and deallocation, validating the count, and handling potential changes to the underlying collection between calls. While the p prefix and this naming pattern are common in legacy and some contemporary codebases, naming conventions vary across projects. See also: pointers, output parameters, Windows API naming conventions.