Checking if a double value is an integer - Swift

Question

I need to check if a double-defined variable is convertible to Int without losing its value. This doesn\'t work because they are of different types:

if self.         


        

Answer 1

The Swifty way:

let cals = [2.5, 2.0]

let r = cals.map{ return Int(exactly: $0) == nil ?  "\($0)" : "\(Int($0))" }

r // ["2.5", "2"]

Answer 2

Simple Solution

I suggest converting the value to Int then to Double and checking the new value

if value == Double(Int(value)) {
// The value doesn't have decimal part. ex: 6.0

} else {
//  The value has decimal part. ex: 6.3

}

Answer 3

extension FloatingPoint {
    var isWholeNumber: Bool { isNormal ? self == rounded() : isZero }
}

let double = 3.0    
double.isWholeNumber        // true
print(3.15.isWholeNumber)   // false

Answer 4

Using mod (%) won't work anymore.

You can now use:

let dbl = 2.0
let isInteger = dbl.truncatingRemainder(dividingBy: 1.0) == 0.0

Answer 5

Swift 3

if dbl.truncatingRemainder(dividingBy: 1) == 0 {
  //it's an integer
}

Answer 6

check if % 1 is zero:

Swift 3:

let dbl = 2.0
let isInteger = dbl.truncatingRemainder(dividingBy: 1) == 0

Swift 2:

let dbl = 2.0
let isInteger = dbl % 1 == 0