The Slider form control in SwiftUI lets us create a bar that the user can swipe left or right to decrease or increase its value.

We initialize a Slider by setting 3 parameters: value, in, step:

@State private var age: Double = 0

//...

Slider(value: $age, in: 0...100, step: 1)

in limits the minimum and maximum values we can use.

step means we can step by a value of 1 at a time, in this case we can go from 0 to 1 to 2 etc. You could use 10, or 0.2, and so on.

Since Slider takes a Double value, by default we increment the decimals too.

Example:

struct ContentView: View {
    @State private var age: Double = 0
    
    var body: some View {
        Form {
            Slider(value: $age, in: 0...100, step: 1)
            Text("\(age)")
        }
    }
}

Notice how I added a Text view to show the value of age.

Since it’s a double, we have lots of decimals.

We could format that, but for this we’ll have another post.