The type system in Objective-C is a little bit more disparate than Swift. This is because the structures and enumerations in Objective-C come from C. Only classes and categories come from the Objective-C extension.
In Swift, structures are very similar to classes, but in Objective-C, they are much more different. Structures in Objective-C are essentially just a way of giving a name to a collection of individual types. They cannot contain methods. Even more restrictive than that, structures can't contain Objective-C types. This leaves us with only basic possibilities:
struct Cylinder {
var radius: Int
var height: Int
}
var c = Cylinder(radius: 10, height: 10)
typedef struct {
int radius;
int height;
} Cylinder;
Cylinder c;
c.radius = 10;
c.height = 5;Structures in Objective-C start with the keyword typedef, which is short for type definition. This is then followed by the struct keyword and the different components of the structure contained within curly brackets...