Initializers

Initializers are special methods that provide different ways to create your struct. All structs come with one by default, called their memberwise initializer – this asks you to provide a value for each property when you create the struct.

You can see this if we create a User struct that has one property:

struct User {
    var username: String
}

When we create one of those structs, we must provide a username:

var user = User(username: "twostraws")

We can provide our own initializer to replace the default one. For example, we might want to create all new users as “Anonymous” and print a message, like this:

struct User {
    var username: String

    init() {
        username = "Anonymous"
        print("Creating a new user!")
    }
}

You don’t write func before initializers, but you do need to make sure all properties have a value before the initializer ends.

Now our initializer accepts no parameters, we need to create the struct like this:

var user = User()
user.username = "twostraws"