The goal of today's module project is to create a Currency Conversion playground that can convert from US dollars (USD) to Canadian dollars (CAD) and Mexican Pesos (MXN).

Get the currency conversion value from Google:

On August 7th, 2019 they were:

$1 USD to $1.33 CAD
$1 USD to $19.70 MXN

Create a new playground in this repository called "CurrencyConverter"

1. Create a currency type enum above the class and below the import statements.

   enum Currency {
       case cad
       case mxn
   }

2. Create a property named currency of type Currency. This will store the current currency type we'll be converting to. Set an initial value of .cad.

3. Create a helper method to calculate the currency based on the Currency using the method signature:

   func convert(_ dollars: Double) -> Double {
   
   }

4. In the above method:

   • Check the value of currency to see whether you should convert to CAD or MXN
   • Perform the conversion with the dollars passed into this method
   • Return the converted value

5. Create a function called convert(amountString: String) In it, do the following:

   • create a constant called amount. Its value should be the amountString that is initialized into a Double
   • use a guard let to unwrap the new amount constant.
   • convert the dollar amount to the expected currency (hint, you'll want to call the convert method you created in step 3)
   • Update the toCurrencyTextField.text property with the converted currency value

1. Customize the output using a NumberFormatter

   var currencyFormatter: NumberFormatter = {
       let formatter = NumberFormatter()
       formatter.numberStyle = .currency
       return formatter
   }()

2. Use the string(from:) method to convert from a number to a String for display