36.2 Implicit Animation
Many of the built-in view types included with SwiftUI contain properties that control the appearance of the view such as scale, opacity, color and rotation angle. Properties of this type are animatable, in that the change from one property state to another can be animated instead of occurring instantly. One way to animate these changes to a view is to use the animation() modifier (a concept referred to as implicit animation because the animation is implied for any modifiers applied to the view that precede the animation modifier).
To experience basic animation using this technique, modify the ContentView.swift file in the AnimationDemo project so that it contains a Button view configured to rotate in 60 degree increments each time it is tapped:
struct ContentView : View {
@State private var rotation: Double = 0
var body: some View {
...
