Swift - How to remove a decimal from a float if the decimal is equal to 0?

I'm displaying a distance with one decimal, and I would like to remove this decimal in case it is equal to 0 (ex: 1200.0Km), how could I do that in swift? I'm displaying this number like this:

let distanceFloat: Float = (currentUser.distance! as NSString).floatValue
distanceLabel.text = String(format: "%.1f", distanceFloat) + "Km"

Swift 3/4:

var distanceFloat1: Float = 5.0
var distanceFloat2: Float = 5.540
var distanceFloat3: Float = 5.03

extension Float {
    var clean: String {
       return self.truncatingRemainder(dividingBy: 1) == 0 ? String(format: "%.0f", self) : String(self)
    }
}

print("Value \(distanceFloat1.clean)") // 5
print("Value \(distanceFloat2.clean)") // 5.54
print("Value \(distanceFloat3.clean)") // 5.03

Swift 2 (Original answer)

let distanceFloat: Float = (currentUser.distance! as NSString).floatValue
distanceLabel.text = String(format: distanceFloat == floor(distanceFloat) ? “%.0f" : "%.1f", distanceFloat) + "Km"

Or as an extension:

extension Float {
    var clean: String {
        return self % 1 == 0 ? String(format: "%.0f", self) : String(self)
    }
}

Use NSNumberFormatter:

let formatter = NumberFormatter()
formatter.minimumFractionDigits = 0
formatter.maximumFractionDigits = 2

// Avoid not getting a zero on numbers lower than 1
// Eg: .5, .67, etc...
formatter.numberStyle = .decimal

let nums = [3.0, 5.1, 7.21, 9.311, 600.0, 0.5677, 0.6988]

for num in nums {
    print(formatter.string(from: num as NSNumber) ?? "n/a")
}

Returns:

3

5.1

7.21

9.31

600

0.57

0.7

extension is the powerful way to do it.

Extension:

Code for Swift 2 (not Swift 3 or newer):

extension Float {
    var cleanValue: String {
        return self % 1 == 0 ? String(format: "%.0f", self) : String(self)
    }
}

Usage:

var sampleValue: Float = 3.234
print(sampleValue.cleanValue)

3.234

sampleValue = 3.0
print(sampleValue.cleanValue)

3

sampleValue = 3
print(sampleValue.cleanValue)

3

Sample Playground file is here.

Update of accepted answer for swift 3:

extension Float {
    var cleanValue: String {
        return self.truncatingRemainder(dividingBy: 1) == 0 ? String(format: "%.0f", self) : String(self)
    }
}

usage would just be:

let someValue: Float = 3.0

print(someValue.cleanValue) //prints 3

To format it to String, follow this pattern

let aFloat: Float = 1.123

let aString: String = String(format: "%.0f", aFloat) // "1"
let aString: String = String(format: "%.1f", aFloat) // "1.1"
let aString: String = String(format: "%.2f", aFloat) // "1.12"
let aString: String = String(format: "%.3f", aFloat) // "1.123"

To cast it to Int, follow this pattern

let aInt: Int = Int(aFloat) // "1"

When you use String(format: initializer, Swift will automatically round the final digit as needed based on the following number.