1. Recitation 8
October 14, 2011

2. Today’s Goals:
Overriding versus overloading a method

3. Notes Show off your work!
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Not Graded

4. Extending the Object class
All classes extend the Object class either directly or indirectly

5. Overloading overloaded methods: appear in the same class or a subclass
have the same name but,
have different parameter lists, and,
can have different return types
[Java Quick Reference]

6. Overloading Object equals()
public boolean equals(Example otherExample) {
if (otherExample != null) {
return (this.getX() == otherExample.getX() && this.getY() ==
otherExample.getY()); }
else return false;
equals defined in Example & Object

7. Overriding Overridden methods: appear in subclasses
have the same name as a superclass method
have the same parameter list as a superclass method
have the same return type as a superclass method
A few other conditions you’ll learn later.
[Java Quick Reference]

8. Overriding Object equals()
public boolean equals(Object obj) {
if(obj instanceof Example && obj != null) {
Example otherObj = (Example)obj;
return (this.getX() == otherObj.getX() && this.getY() ==
otherObj.getY()); }
else return false;
equals defined in Example

9. Overriding & Overloading Object equals()

10. Recitation Specification
Add equals(…) to CartesianLine which overloads Object.equals()
Add equals(…) to CartesianTriangle which overrides Object.equals()
Bonus (for candy): Make equals work in a graphical sense.