SwiftUI Academy · Lesson

Avoiding Unnecessary Redraws

Scope state to minimize body re-evaluations.

The Cost of Over-Updating

If a tiny change forces a huge view to rebuild, scrolling stutters. The fix is to keep each redraw as small as possible.

Put @State in the smallest view that owns it. Then only that little view re-evaluates when the value flips, not its big parent.

struct Counter: View {
    @State private var count = 0
}