satan87

// MARK: IF FILTER
var bookBefore2000 = [Book]()
for book in books {
    if book.year < 2000 {
        bookBefore2000.append(book)
    }
}

satan87

// MARK: HIGHER ORDER FUNCTION
let bookBefore2020HOF = books.filter({$0.year < 2000})

satan87

struct SearchingBook {
    var byBeforeYear = 0 //0 meaning do not filter on this
    var byFavorite = FavoriteSearch.all
    var byAuthorFirstName = ""
}

satan87

enum FavoriteSearch {
    case all
    case favorite
    case notFavorite
}

satan87

func filterBooks(books: [Book], by filters: SearchingBook) -> [Book]

satan87

// MARK: FILTER FUNCTION
func filterBooks(books: [Book], by filters: SearchingBook) -> [Book]{
    
    var bookFiltered = books.filter({ filters.byBeforeYear == 0 || $0.year < filters.byBeforeYear})
    
    //Search by favorite
    switch filters.byFavorite {
    case .favorite:
        bookFiltered.removeAll(where: {!$0.favorite})
    case .notFavorite:

satan87

var bookFiltered = books.filter({ filters.byBeforeYear == 0 || $0.year < filters.byBeforeYear})

satan87

switch filters.byFavorite {
case .favorite:
    bookFiltered.removeAll(where: {!$0.favorite})
case .notFavorite:
    bookFiltered.removeAll(where: {$0.favorite})
default:
    break
}

satan87

if !filters.byAuthorFirstName.isEmpty {
  bookFiltered.removeAll(
      where: {$0.author.firstName.range(of: filters.byAuthorFirstName, options: .caseInsensitive) == nil})
}

satan87