object vs. class! - politehnica university of...

Objects and Classes

Suggested Reading: Bruce Eckel, Thinking in Java (Fourth Edition)Introduction to Objects, Everything is an Object

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An example in C...

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Same example in Java...

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Object-oriented programming is a method of implementation in which programs are organized as cooperative collections of objects, each of which represents an instance of some class, and whose classes are all members of a hierarchy of classes united via inheritance relations.[G. Booch et al. Object-Oriented Analysis and Design with Applications. 3rd edition, 2007.]

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Object vs. Class!

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An Object has...

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Identity(memory address)

Interface(known by its user)

Behavior(known by its implementer)

State(given by its attributes)

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Access Specifiers

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X

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A Constructor

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has the same name as the class it belongs to

does not return a value(neither void)

is called only when a class is instantiated

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A constructor was added...

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Static Members

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Static Members

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Final Members

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Unified Modeling Language (UML) - an example