Question

For example I have 3 books:
Booknumber (int), Booktitle (string), Booklanguage (string), Bookprice (int).

Now, I want to have an array called books[3][4]. I’m getting the data I set via setBooknumber like this:
Book1.getBooknumber(), Book1.getBooktitle(),...,Book3.getBookprice().

How do I realize this: books[3][4] array.

I can’t call it String books[][] = new String [3][4]. Because I can’t get Booknumber (int) into it. I don’t want Booknumber to be String neither Bookprice. How do I realize it, please?

To further elaborate it. I have 2 classes: book and bookUI.

book

public class book{
String Booktitle, Booklanguage;
int Booknumber, Bookprice;

//constructor

//get

//set
}

bookUI

public class bookUI
{
 public static void main(String arg[])
 {
   book book1 = new book();
   book book2 = new book();
   book book3 = new book();

   book1.setBooktitle();
   ...
   book3.setBookprice();

   //Here I want to have books[3][4] Array. And gettin the data via book1.get...book3.get into the array
 }
}

Answer 1

public class Book
{
    public int number;
    public String title;
    public String language;
    public int price;

    // Add constructor, get, set, as needed.
}

then declare your array as:

Book[] books = new Book[3];

EDIT:
In response to O.P.’s confusion, Book should be an object, not an array. Each book should be created on it’s own (via a properly designed constructor) and then added to the array. In fact, I wouldn’t use an array, but an ArrayList. In other words, you are trying to force data into containers that aren’t suitable for the task at hand.

I would venture that 50% of programming is choosing the right data structure for your data. Algorithms naturally follow if there is a good choice of structure.

When properly done, you get your UI class to look like:
Edit: Generics added to the following code snippet.

...
ArrayList<Book> myLibrary = new ArrayList<Book>();
myLibrary.add(new Book(1, "Thinking In Java", "English", 4999));
myLibrary.add(new Book(2, "Hacking for Fun and Profit", "English", 1099);

etc.

now you can use the Collections interface and do something like:

int total = 0;
for (Book b : myLibrary)
{
   total += b.price;
   System.out.println(b); // Assuming a valid toString in the Book class
}
System.out.println("The total value of your library is " + total);