1. SE-1021 Software Engineering II
CS-1020
5/14/2019
SE-1021 Software Engineering II
Week 1, Day 3
Quiz
Name sheet
Emergency Response Plan Completed
Inheritance
Defined
Examples
In memory
In code
In use
SE-2811
Dr. Josiah Yoder
Slide style: Dr. Hornick
Dr. Mark L. Hornick

2. Emergency Response PlanCC
Outside: Broadway Lot by blue phone
Inside: Cafeteria
S (Science/Engineering Center)
Tornado: Primary: Lowest Level Possible - Hallway, Alternate: Center Stairwell
Outside: State Street A Lot
Inside: CC, 3rd Floor
SE-2811
Dr. Josiah Yoder
Slide style: Dr. Hornick

3. Relationships (between classes)
Inheritance
Aggregation
Composition
SE-2811
Dr. Josiah Yoder
Slide style: Dr. Hornick

4. Slide style: Dr. Hornick
Inheritance defined
Inheritance
(In life) The act of inheriting
(In Java) The act of inheriting
Inherit
(In life) Receive possessions from previous generations
(In Java) Receive common features defined by a “parent” class
SE-2811
Dr. Josiah Yoder
Slide style: Dr. Hornick

5. Slide style: Dr. Hornick
How it works
The “base” class defines traits common to many classes
The “derived” class defines specialized features. It automatically has all the features defined in the base class
SE-2811
Dr. Josiah Yoder
Slide style: Dr. Hornick

6. Slide style: Dr. Hornick
Example 1: Graphics
Shape
Base class: Shape
Defines position of the shape on the screen
Derived class: Circle
Defines radius of the circle
Position is inherited from Shape, so Circle doesn’t define it
A circle “is a” shape
-centerX: double
-centerY: double
Circle
-radius: double
SE-2811
Dr. Josiah Yoder
Slide style: Dr. Hornick

7. Example 2: Game Characters
CS-1020
5/14/2019
Example 2: Game Characters
Animal
Base class: Animal
Defines eat() behavior
Derived class: Bird
Defines fly() behavior
Inherits eat() behavior
+eat(): void
Bird
+fly(): void
SE-2811
Dr. Josiah Yoder
Slide style: Dr. Hornick
Dr. Mark L. Hornick

8. Example 3: Machine Parts
Base class: Part
Defines material
Size ID
Derived class: Gear
Defines mesh()
Inherits without defining:
Material, size, ID
Introduce yourselves
Fill in the blanks above
Gear
SE-2811
Dr. Josiah Yoder
Slide style: Dr. Hornick

9. Slide style: Dr. Hornick
UML In memory
shape1
circle
shape2
Shape
Shape ref
Shape ref
Shape ref
-centerX: double
-centerY: double
centerX
centerX
3.0
3.0
double
double
centerY
centerY
4.0
4.0
Circle
double
double
Shape
-radius: double
radius
1.5
double
SE-2811
Dr. Josiah Yoder
Slide style: Dr. Hornick
Shape

10. Slide style: Dr. Hornick
Example 1 Continued
Shape
Base class: Shape
Defines constructor
Defines toString
Derived class: Circle
Overrides toString
-centerX: double
-centerY: double
+Shape(x: double, y: double)
+toString(): void
Circle
-radius: double
+Shape(x:double, y:double, r: double)
+toString(): void
SE-2811
Dr. Josiah Yoder
Slide style: Dr. Hornick

11. Slide style: Dr. Hornick
In Code
SE-2811
Dr. Josiah Yoder
Slide style: Dr. Hornick