在 Swift 中将 Int 转换为 Double

Question

label.text = String(format:"%.1f hour", theOrder.bookingMins/60.0)

The above code just get the error: 'Int' is not convertible to 'Double'

bookingMins is of type Int, so how do I convert an Int to a Double in Swift? Seems not as simple as in C.

Answer 1

尝试Double(theOrder.bookingMins)

Answer 2

What I prefer to do is to use computed properties. So I like to create an extension of Double and than add a property like below:

extension Int {
  var doubleValue: Double {
    return Double(self)
  }
}

And than you can use it in very Swifty way, I believe in future updates of swift language will be something similar.

let bookingMinutes = theOrder.bookingMins.doubleValue

in your case

label.text = String(format: "%.1f hour", bookingMinutes / 60.0) 

Style guide used: https://github.com/raywenderlich/swift-style-guide

Answer 3

label.text = String(format:"%.1f hour", Double(theOrder.bookingMins) /60.0)

Answer 4

Swift 4/5

let mins = Double(theOrder.bookingMins)
label.text = String(format:"%.1f hour", mins/60.0)

Answer 5

Swift 5 (Basic to Convert Int to Double)

let a = 3, let b =4

func divide ( number1 : Int, number2 : Int)
{
let divide = Double (number1) / Double (number2)
print (divide)

}

The output should be 0.75