Object Oriented Programming using Java - Composition

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Object Oriented Programming using Java-
Composition
Department of Computer and Information
Science,School of Science, IUPUI
Dale Roberts, Lecturer Computer Science,
IUPUI E-mail droberts_at_cs.iupui.edu
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Composition

• Composition
• A class can have references to objects of other
  classes as members
• Sometimes referred to as a has-a relationship
• One form of software reuse is composition, in
  which a class has as members references to
  objects of other classes.

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Outline

• Date.java
• (1 of 3)

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Outline
Validates month value

• Date.java
• (2 of 3)

Validates day value
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Outline

• Date.java
• (3 of 3)

Check if the day is February 29 on a leap year
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Outline

• Employee.java

Employee contains references to two Date objects
Implicit calls to hireDate and birthDates
toString methods
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Outline

• EmployeeTest.java

Create an Employee object
Display the Employee object
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Acknowledgements

• Deitel, Java How to Program