static void Main(string[] args)
{
// calculate the average tax rate of internal and external invoices using adapter pattern
var inv1 = new Invoice()
{
InvoiceNo = 1
};
var inv2 = new ExternalBillingDocument()
{
DocumentNumber = "E2", TaxRatePercent = "25"
};
IList <ITaxRate> invoices = new List <ITaxRate>()
{
inv1,
new ExternalBillingDocumentTaxRateAdapter(inv2)
};
var avgTaxRate = invoices.Average(x => x.TaxRate());
Console.WriteLine($"The average tax rate is {avgTaxRate}.");
Console.ReadKey();
}
public ExternalBillingDocumentTaxRateAdapter(ExternalBillingDocument document)
{
_document = document;
}