Creates and returns an
NSMutable object with enough allocated memory to initially hold a given number of objects.
- iOS 2.0+
- macOS 10.0+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
The initial capacity of the new array.
NSMutable object with enough allocated memory to hold
Mutable arrays expand as needed;
num simply establishes the object’s initial capacity.