kCFNumber

kCFNumber is a constant used in Apple's Core Foundation framework to indicate that a CFTypeRef object represents a number. Core Foundation is a low-level C-based API that provides data management and service functionalities. When you encounter a CFTypeRef with the type identifier kCFNumber, it signifies that the underlying data is a numerical value.

Numbers in Core Foundation can represent various numeric types, such as integers, floating-point numbers, and booleans. The specific type of number is determined by the underlying C type or Objective-C class that the kCFNumber represents. For example, it could be an NSInteger, CGFloat, or a primitive C type like int or float.

To work with a kCFNumber, you typically need to cast the CFTypeRef to a CFNumberRef. Once you have a CFNumberRef, you can query its specific numeric type and extract its value. This is often done using functions like CFNumberGetType and CFNumberGetValue. These functions allow you to safely retrieve the numerical data in a format that your C or Objective-C code can understand.

kCFNumber is fundamental for handling numerical data within the Core Foundation ecosystem, enabling interoperability between different parts of the system and facilitating the storage and manipulation of numerical information in a type-safe manner. It is a key component for developers working with low-level Apple frameworks.