I am at 100 days of swiftUI, day 54.

import SwiftUI

struct RatingView: View {
    @Binding var rating: Int

    var offImage: Image?
    var onImage = Image(systemName: "star")

    var offColor = Color.gray
    var onColor = Color.yellow

    var body: some View {
        HStack{

            ForEach(1..<6 , id: \.self){number in
                image(for: number)
                    .foregroundStyle(number > rating ? .gray : .yellow)
                    .onTapGesture {
                        rating = number
                    }
            }
        }
    }
    func image(for number: Int) -> Image {
        if number > rating {
            return offImage ?? onImage
        } else {
            return onImage
        }
    }
}

#Preview {
    RatingView(rating: .constant(4))
}

this is the code explained in the course. I cant understand why we used offImage and image function. Why can't i use onImage directly in ForEach like this:

ForEach(1..<6 , id: \.self){number in
                onImage
                    .foregroundStyle(number > rating ? .gray : .yellow)
                    .onTapGesture {
                        rating = number
                    }
            }

I understood that offImage will always be nil and image function will alwais return onImage, am I wrong?