I have my code below and I am attempting to create new arrays, in which the numbers in the elements increment by 1 whenever the user adds a book. For instance, when the user already has 1 book added and when he adds another one the array should read as `["bookTitle2,"bookAuthor2", "bookPublisher2", "bookNumOfPages2"]` 

```
let bookDetails = ["bookTitle", "bookAuthor", "bookPublisher", "bookNumOfPages"]
var bookDetail = ""
var bookNumber = Int()
var bookNumArray = [Int]()

if bookNumArray.contains(bookNumber) {

print("Book already exists")

} else {

while bookNumber < 2 {

    bookNumber += 1

    bookNumArray.append(bookNumber)

    for detail in bookDetails {

        bookDetail = "\(detail)" + String(bookNumber)

        let newBookArray = [bookDetail]

        print(newBookArray)

    }

}

    }

```

When I run the code above, this shows up instead:

```
["bookTitle1"]
["bookAuthor1"]
["bookPublisher1"]
["bookNumOfPages1"]
["bookTitle2"]
["bookAuthor2"]
["bookPublisher2"]
["bookNumOfPages2"]

```

So I want all the strings that end with 1 in one array and those that end in 2 in another array.