We generalize a collection of many similar objects into one general type (or class).

The word "general" is key in object thinking. 💡

Summary Table:

ConceptAlso CalledCountQuick Description
TypeClass (Next Chapter)OneA single definition (e.g. "Person")
ObjectInstanceZero to manyActual person objects. For example: "Zada", "Yang", "Yawo", "Bob", ...
PropertyField, Varibable, or AttributeZero to many for a given typeAspects of an object like "width" and "height" (e.g. for a Rectangle type)


You can define any object type (class) you like. Just a few examples here to give you an idea: Airplane, Baby, Bird, Car, City, College, CollegeApplication, Computer, Country, House, Lake, Person, Player, Rectangle, Road, Student, Team, Train, etc.

Another way to look at it is to think of a general type (class) is like a "blueprint" or "plan". We have one "blueprint" idea for say a bicycle that can be used to construct many actual bicycles. Some parts of the individual bikes may vary (e.g. color), but they all follow the pattern of the blueprint.





























Introduction To Objects With Java (Chapter 301 - Object Types and Objects)










Chapter 301 - Object Types and Objects Summary

Chapter Contents Overview Objects Object Types Properties Summary Refs Examples

Chapter Top Search TOC