CFNumberCreateNULL

CFNumberCreateNULL is a function provided by the Core Foundation framework in Apple's operating systems, including macOS, iOS, watchOS, and tvOS. Its primary purpose is to create a special type of CFNumber object that represents a null value. This is distinct from other numerical types that CFNumber can represent, such as integers or floating-point numbers.

When you call CFNumberCreateNULL, it returns a reference to a CFNumber object that has no specific numerical value assigned to it. This can be useful in situations where you need to represent the absence of a number within a Core Foundation data structure, such as a CFDictionary or an array. It allows for a consistent way to handle missing or undefined numerical data.

The returned object is a singleton, meaning that all calls to CFNumberCreateNULL will return the same underlying object. This ensures memory efficiency. It is important to note that while this object represents a null value, it is still a valid CFNumber object and should be managed accordingly within the Core Foundation memory management model. You do not typically need to release the object returned by CFNumberCreateNULL.