private List <Book>[] GetArrayWithListsOfAllBooksInEachAgeGroup()
{
var allBorrows = borrowManager.GetAllBorrows();
List <Book>[] books = new List <Book> [10];
int a = 0;
for (int i = 9; i < 100; i += 10)
{
books[a] = new List <Book>();
foreach (Borrow borrow in allBorrows)
{
int age = DateTime.Now.Year - borrow.Customer.DateOfBirth.Year;
if (age <= i && age > (i - 10))
{
books[a].Add(borrow.Book);
}
}
a++;
}
return(books);
}
private List <Borrow> GetListOfAllBorrowsLastSixMonths()
{
return(borrowManager.GetAllBorrows().FindAll(b => b.DateOfBorrow >= DateTime.Today.AddMonths(-6)));
}