((Book)item1).display();
Answer:
Because you want to:
- First, cast
item1to typeBook. - Then, invoke the
display()method that objects of typeBookhave.
((Book)item1).display();
Because you want to:
item1 to type Book.display() method that objects of type Book have.Now examine the following:
public class Store
{
public static void main ( String[] args )
{
Book book ;
Taxable tax = new Book ( "Emma", 24.95, "Austen" );
book = tax;
book.display();
System.out.println( "Tax on item 1 "+ book.calculateTax() );
}
}
Is a type cast necessary? Where should it go?