iOS - Cannot assign value of type 'Double' to type 'Float'

Question

I have trouble with variable types to declare and use constants.

let MAX_RADIUS_IN_MILE = 100.0

radiusSlider.maximumValue = MAX_RADIUS_IN_MILE

In this case, I get an error - Cannot assign value of type 'Double' to type 'Float'

I don't want to declare a constant with a type definition like this let MAX_RADIUS_IN_MILE: Float = 100.0 but just wanna know another smart way to do make this constant as Float.

Any idea?

For example, C# has a solution for this.

Answer 1

First, use camelCase for naming in Swift. lowerCamelCase for constants/variables/functions and UpperCamelCase for types (classes, ...)

MAX_RADIUS_IN_MILE -> maxRadiusInMile

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Now to your problem. Error is clear, you have constant of type Double (if you don't specify type of decimal number, compiler give it type Double ), but assigning maximumValue requires type Float . What now?

One solution if you need your constant to be of type Float is: specify type of your constant as Float

let maxRadiusInMile: Float = 100
let maxRadiusInMile = Float(100)

Anyway, if you need this constant just for assigning one value, use can assign it directly

radiusSlider.maximumValue = 100

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If you from some reason need your constant to be of type Double , then you can convert your constant of type Double to Float using designed initializer

let maxRadiusInMile = 100.0
radiusSlider.maximumValue = Float(maxRadiusInMile)