1. Haidong Xue Summer 2011, at GSU
Principles of Computer Programming (using Java) Chapter 10 Writing Classes
Haidong Xue
Summer 2011, at GSU

2. Content Test2 Information Hiding Life scope and visible scope
Method Overloading
Constructor and variable initialization

3. Test 2
Average: 71.6
[0, 60) : 10
[60, 80): 9
[80, 100]: 9
Answers

4. Information Hiding What is information hiding? Why? Rule:
Easy to test and debug
Easy to maintain
Protect variables from invalid values
Rule:
Generally, always make the member variables private

5. Life scope and visible scope
Member variables
Local variables
Parameter variables
Objects
Hidden variables
Reason: same names
Solution: using this

6. Method overloading What is method overloading? Signature
Name, and the type of parameters

7. Constructors and variable initialization
How to initialize the member variables?
What is member variable initialization?
What if there is no initialization at all?
The default values?
What if there is a conflict?
The initialization order
Using constructors in constructors

8. Next class
Inheritance
Overriding
Polymorphism
“Object” class

9. Assignment 7
Improve previous assignments, using the knowledge you learnt today.