toolItem[]tool = new toolItem[10]; parent/abstract class (not same definition as obj. cant have obj. of it) goal is to create multiple child classes in abstract display can have nothing in it (I'm familiar with this such as much like Alien and Marine are classes of Parent Abstract class labeled with the keyword abstract can not itself be instantiated has one or more methods that are labeled abstract and are headers only acts as super class for many related classes each of which can use all the methods of the abstract class top of file has public abstract class Shape (Shape is class so rename it accordingly) Abstract is a generic shape class public void (not empty) publid void (not empty) public void (not empy) public draw ( empy, must be replaced by child ) child has public void draw( Graphics g, Container c ) { } the only one that the child has to implement in is the required one because public class Spot extends Shape -- class defined as a subclass of the abstract shape so the class spot wont need sets and gets because it parent has them. if theres an abstract method in in the abstract class then the child class must use that abstract method publilc class Fly extends Shape public void draw (replace) private Shape[] shaes = new Shape[2]; shapes[0] = new Fly(); shapes[1] = new Spot(); shapes[0].draw (fly class) shapes[1].draw (spot class) Polymorphism when two or more classes have mmethods of the same name. When the BaseballPlayer is abstract class *******PURPOS ((Parent empty so child has to replace)) E********** ((Child has purpose method)) -Position ((written on board)) -Name -# -Team -bat % -glove side -batting side keep the same instance variables (data members) keep the same get and set methods write the calcAverage and getAverage methods as abstract and static methods write displayData method as abstract and static PositionPlayers as a subclass of BaseballPlayer Define class Picture as a subclass of BaseballPlayer public abstract class BaseballPlayer { public static void calcAverage(); //static // creates no objects public static void displayData(); //static //creates no objects } create an array of players public class BaseballTeam { BaseballPlayer[] team = new BaseballPlayer[10]; int numPlayer = 0; if(position == 'P') //.equals? { team[numPlayer] = new Pitcher(pass in data); // numPlayer++; } else { team[numPlayer] = new PositionPlayer(pass in data); numPlayer++; } //or switch if more than 2 } Layout manager is a class that controls the positioning and sizing of window objects in a container FlowLayout BorderLayout GridLayout GridBagLayout BoxLayout Cardlayout Container c = getContentPane(); c.setLayout(new FlowLayout()); - eventually BorderLayout public class calcarea { private JPanel eastPanel, westPanel, centralPanel setBorderLayout(); //better to set the panels by panels groued together eastPanel = new JPanel(); //bkrnd color JLabel promptLbl eastPanel.add(promptLbl); //then panel is added to container c.add(eastPanel, BorderLayout.EAST); westPanel = new JPanel(); ~~ ~~~ ~~ westPanel.add(circleBtn); c.add(westPanel, BorderLayout.WEST) ~~~~~~~~~~~~~~~ JOPtionPane.showMessageDialog(centerPanel, -- null is changed to say where west center east startX startY endX endY debug with system.print as usual dont force abstract class if i have easy way to do it then ...