SOLVED: Unwrapping Double? in Binding – SwiftUI – Hacking with Swift forums

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SOLVED: Unwrapping Double? in Binding

Forums > SwiftUI

	@casj_swift May '23 Hi all, In the following code, I want to force-unwrap a `Double?`, `radii.1` (the one in the Slider): `if shape.radii.1 != nil { Slider(value: $shape.radii.1, in: 100...150) }` However, just adding an exclamation mark after `radii.1` in the Slider doesn't work, because then Swift throws an error, which as far as I understand means that it thinks that I want to unwrap the whole Binding instead of the optional `radii.1`. Does anyone know how to fix this? 2
	@Obelix May '23 @Cas is sliding into trouble: I want to force-unwrap a Double?, the one in the Slider Take a look at SwiftUI documentation for a `Slider` initializer. (This is a skill you need to learn!) See -> Official Slider Documentation `init<V>( value: Binding<V>, in bounds: ClosedRange<V> = 0...1, onEditingChanged: @escaping (Bool) -> Void = { _ in } ) where V : BinaryFloatingPoint, V.Stride : BinaryFloatingPoint // <--- READ THE FINE PRINT` The initializer will build a `Slider` that slides over a range of type (V) and save the selected value to a binding also of type (V). The fine print however says that type must conform to the `BinaryFloatingPoint` protocol. Even if you check to see that your Optional-Double does not contain `nil`, you should understand the compiler still sees the variable as an Optional-Double. Values of type Optional-Double do not conform to the `BinaryFloatingPoint` protocol. 2
	@NigelGee HWS+ May '23 `@casj_swift` What is `.1`? Does it need to be optional can you give it a deflaut value (say 125)! 2
	@Obelix May '23 @Nigel prompts a review of Tuples! What is .1? See -> Tuple 2
	@casj_swift May '23 Thank you for your reactions. I fixed it by making the optional a non-optional and giving it a default value, like NigelGee suggested. 2
	@NigelGee HWS+ May '23 `@Obelix` yes but you can put labels on Tuples so that they are more readable then `.1` eg `(xAxis: Double, yAxis: Double)` then it would read `$shape.radii.yAxis` 2

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