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What's the difference between `geometryReader` and retrieving screen width using `UIScreen`? What's so special about `GeometryReader?`

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What's the difference between geometryReader and retrieving screen width using UIScreen? What's so special about GeometryReader?

Example 1

GeometryReader { geometry in
    HStack(spacing: 0) {
        Text("Left")
            .font(.largeTitle)
            .foregroundColor(.black)
            .frame(width: geometry.size.width * 0.33)
            .background(Color.yellow)
            }
            }

Example 2

HStack(spacing: 0) {
        Text("Left")
            .font(.largeTitle)
            .foregroundColor(.black)
            .frame(width: UIScreen.main.bounds.size.width * 0.33)
            .background(Color.yellow)
            }

1      

UIScreen will always give you the dimensions of the entire screen.

A GeometryReader will give you the dimensions of whatever View contains it. That could be the entire screen, or it could be just a part of the screen. It all depends on where you put the GeometryReader in your view hierarchy.

The two methods are used for different purposes that sometimes result in the same values but do not necessarily have to.

1      

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