Initializing the Arrays
The data that will be used in our application is stored in two arrays, one for the country name and the other for the corresponding exchange rate. In the real world, the application would likely obtain up-to-date exchange rate information from an external source, but for the purposes of this example we will hard code the prevailing rates at the time of writing. These arrays need to be initialized when the application loads, so the necessary code should be added to the viewDidLoad method of the PickerViewController.m file: