Swift playground - How to convert a string with comma to a string with decimal

Question

I\'m new in the Swift world.

How can I converting a String with a comma to a String with a decimal?

The code work\'s fine with a dot (.)

The problem

Answer 1

Nullable extension version:

extension String 
{
    static let customNumberFormatter = NumberFormatter()
    var doubleValue: Double? {
        String.customNumberFormatter.decimalSeparator = "."
        if let result =  String.customNumberFormatter.number(from: self) {
            return result.doubleValue
        } else {
            String.customNumberFormatter.decimalSeparator = ","
            if let result = String.customNumberFormatter.number(from: self) {
                return result.doubleValue
            }
        }
        return nil
    }
}