In Swift, an enumeration defines a common type for related values and enables us to work with those values in a type-safe way. Values provided for each enumeration member can be a String, Character, Integer, or any floating-point type. The following example presents a simple definition of an enumeration:

enum MLSTeam {
    case montreal
    case toronto
    case newYork
    case columbus
    case losAngeles
    case seattle
}

let theTeam = MLSTeam.montreal

MLSTeam enum provides us options for MLS teams. We can choose only one of the options each time; in our example, Montreal is chosen.

Multiple cases can be defined, separated by a comma on a single line:

enum MLSTeam {
    case montreal, toronto, newYork, columbus, losAngeles, Seattle
}

var theTeam = MLSTeam.montreal

The type of theTeam is inferred when it is initialized with MLSTeam.montreal. As theTeam is already defined, we can change it with a shorter syntax as follows:

theTeam = .newYork

We were able to change theTeam with a short syntax because theTeam was already inferred and was not a constant.