public class TestBook {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		
		Book book1= new Book();
		
		System.out.println("Plain book object: "+book1);
		
		book1.setAuthor("Isaac Asimov");
		book1.setTitle("End of the Eternity");
		book1.setPageCount(450);
		
		System.out.println("After setting  book object: "+book1);
		
		
		
		Book book2= new Book("Isaac Asimov","End of the Eternity",450);
		
		// == returns true only when the variables refer to the same object
		// Here although the objects are identical == returns false because they are different objects
		if(book1==book2){
			System.out.println("== opeator says the books are the same");
		}
		else{
			System.out.println("== opeator says the books are not the same");
		}
		
		// You can define equals method to do arbitrary equality checking 
		if(book1.equals(book2)){
			System.out.println("equals() method says the books are the same");
		}
		else{
			System.out.println("equals() method says the books are not the same");
		}
		
		
		
		Book book3 = book2;
		if(book3==book2){
			System.out.println("book3 and book2 refer to the same object");		
		}
		else{
			System.out.println("book3 and book2 don't refer to the same object");
		}
		
		
		
		Book dune=new Book("Frank Herbert","Dune",350);
		dune.setCurrentPage(300);
		dune.turnPage();
		dune.turnPage();
		System.out.println(dune.getCurrentPage());
		System.out.println(dune.getEstimatedTimeLeft());
		
		// references and call by value. The modifications made to the object inside the method is also visible outside.
		System.out.println(dune);
		changeAuthor(dune);
		System.out.println(dune);
		
		// static variables are shared by all objects of the class.
		System.out.println(book1.description);
		System.out.println(book2.description);
		Book.description="Empty description";
		System.out.println(book1.description);
		System.out.println(book2.description);
		
		

	}
	
	
	private static void changeAuthor(Book b){
		b.setAuthor("Dr. Aronis");		
	}
	

}