In addition to the init() method, we can also provide our structs with custom methods that instances can call. These instance methods are created like a normal function but within the scope of the structure itself:

struct Dog {
  var age : Int
  var isGood : Bool

  init(age: Int, isGood: Bool) {
    self.age = age
    self.isGood = isGood
  }

  // We've added a bark() method:
  func bark() {
    print("woof")
  }
}

In the example above, we added a method bark() using the func keyword — it doesn’t have any parameters, nor does it return anything. The method syntax looks like exactly of function, the major difference being a method is specific to the structure’s instances.

Great, now we can create an instance of Dog that has the .bark() method:

var bucket = Dog(age: 4, isGood: true)
bucket.bark() // Prints: woof

After we defined our instance, bucket, we can call the method using dot syntax and a pair of parentheses after the method name.