1. Using Objects

2. Java Primitive Data Types
integral
boolean
floating point
byte char short int long float double
Begin with lowercase letters

3. Java Reference Types
Reference types:
1. String
2. Class name

4. String Methods int n = greeting.length();
String bigRiver = river.toUpperCase();

5. What is:
Java Syntax??

6. Multiple variables can be created in
variable name
data type
int total;
int count, temp, result;
Multiple variables can be created in
one declaration

7. What Does a Variable Declaration Do?
int ageOfDog;
4 bytes for ageOfDog

8. Variables initial value in the declaration int sum = 0;
int base = 32, max = 149;

9. Assignment
ageOfDog = 10;

10. Variable Declarations and Assignment of Values
ASSIGNMENT STATEMENTS

11. Identifiers
Rules for identifiers in Java?

12. package movetester;
import java.awt.Rectangle;
public class MoveTester {
public static void main(String[] args)
Rectangle box = new Rectangle(5, 10, 20, 30);
// Move the rectangle where x becomes 20 and y becomes 35
box.translate(15, 25);
// Print information about the moved rectangle
System.out.println(box.getX());
System.out.print("y: ");
System.out.println(box.getY());
System.out.println("Expected: 35"); } }

13. Packages
package areatester;

14. We work with Objects A fundamental entity in Java.
Objects are “things”

15. java.lang.Object: the root of java classes

16. Class Object Class encapsulates objects work together (behavior)
Objects have properties:

17. HomeWork P2.1 - Programming Exercise

18. Graphical User Interfaces
GUI Objects

19. Graphical User Interfaces (GUI): Demonstrates the object concep0t!
frame
Graphical User Interfaces (GUI): Demonstrates the object concep0t!
Content pane used to display objects in a frame

20. Example: Frame Viewer 01: import javax.swing.JFrame; 02:
03: public class EmptyFrameViewer
04: {
05: public static void main(String[] args)
06: {
07: JFrame frame = new JFrame();
08:
09: frame.setSize(300, 400);
10: frame.setTitle("An Empty Frame");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
12: frame.setVisible(true);
14: }
15: }
(page 56 of text) or section 2.11
Example: Frame Viewer

21. frame = new JFrame (name);
Jframe frame
Point to object
frame = new JFrame (name);
(creates a class instance)

22. See Sun site for
greater detail
Sun.java

23. Lab 2:Graphical Fun
Using the example in your text book on page 64; Section 2.13:
Create your own FaceViewer Class with a main method that will show a JComponent.
Adjust your Frame to be square
The frame title must contain your name.
Using the FaceComponent example as a guide (page 64; Section 2.13):
Create an Animal Viewer and draw an animal of your choice.
Draw a string that describes the animal
Set colors as desired

24. Upload to the appropriate dropbox
Output
Two classes - tested
Upload to the appropriate dropbox
Lab Completion

25. Object Lessons?