CHAPTER 26 -- Object References

This chapter discusses object reference variables. These variables refer to objects (as opposed to holding a primitive data value.) This chapter discusses object references in greater detail than you have seen so far.

It is important to understand how an object reference variable differs from a primitive variable. Nearly every program you write will require you to know this. Unfortunately, the topic can get confusing if you rush through it too quickly. Don't do that.

Chapter Topics:

• Primitive data types, and objects.
• Object references and object reference variables.
• Copying object references.
• The == operator and object references.
• The equals() operator for strings.

Chapter five discussed the idea of a data type in Java:

Computer memory stores bit patterns. A particular pattern has meaning only when you know what type of value it represents, and what scheme is being used to represent values with patterns. The scheme that is being used for a particular section of memory is a data type.

QUESTION 1:

(Review:) In Java, a piece of data either is of a _________________ data type or is an ________________ data type.