function.swift

var current_time = String(DateFormatter.localizedString(
                            from: Date(), 
                            dateStyle: .none, 
                            timeStyle: .medium))
current_time = current_time.replacingOccurrences(of: ".", with: ":")

// change into function
func getCurrentTime()->String{
    var start_time = String(DateFormatter.localizedString(
                                from: Date(), 
                                dateStyle: .none, 
                                timeStyle: .medium))
    return start_time.replacingOccurrences(of: ".", with: ":")
}
print(start_time)
print(getCurrentTime())