Practice Coding Questions

1. Define an abstract class called Shape. Make it mandatory that every
   sub-class has a method void drawShape( ) and String typeOfShape( ). The
   class Shape should have one instance variable (that will be inherited)
   called the_char, of type char. You should also keep track of the number
   of Shape class objects instantiated (use a static counter variable).
   Shape should have a constructor and finalizer.
2. Define a (non-abstract i.e. concrete) sub-class Square. It should also
   keep track of the number of Square class objects instantiated and have a
   constructor and finalizer. The method void drawShape( ) use the instance
   variable the_char and the method System.out.println to draw a square.
   String typeOfShape( ) should return "Square"
3. Define a class with a main method. The main method should allow the
   user to enter a name and date of in one JOptionPane in the form

   Smith, Henry born 3/4/1978

   In a JTextArea display the message "Hello Henry Smith" (use the person's name
   in place of Henry Smith) and tell them how many years old they are.
4. Make your own special array class called ArrayClass. It should have an int array
   reference as an instance variable. It should have
   • A constructor that accepts an array and makes the instance variable
     an identical array.
   • A toString() method that returns the int values stored in the
     array instance variable concatenated into a string
   • A toString(int i, int j) method that returns the int values stored
     in the array instance variable from index i to index j concatenated
     into a string
   • A getInt(int i) returns i'th entry in array instance variable
   • A setInt(int i) sets the i'th entry in the array instance variable
     equal to i
   • A getLength() method
5. Define a class called Currency. It should keep how many dollars foriegn
   currencies and methods to do conversions of foriegn currencies to us dollars
   and vice-versa. Define the public final instance variables and public methods
   • CANADIANDOLLAR=.85
   • FRENCHFRANC=.23
   • BRITISHPOUND=1.6
   • double canadianToUs( double amountInCanadianDollars )
   • double usToCanadian( double amountInUsDollars )
   • double frenchToUs( double amountInFrancs )
   • double usToFrench( double amountInUsDollars )
   • double britishToUs( double amountInPounds )
   • double usToBritish( double amountInUsDollars )
   Why should all these methods and final instance variables be static?