The Java™ Tutorial Fourth Edition: A Short Course on the Basics

Chapter 3. Language Basics

Variables

As you learned in the previous chapter, an object stores its state in fields.

int cadence = 0;
int speed = 0;
int gear = 1;

The What Is an Object? section (page 33) introduced you to fields, but you probably still have a few questions, such as: What are the rules and conventions for naming a field? Besides int, what other data types are there? Do fields have to be initialized when they are declared? Are fields assigned a default value if they are not explicitly initialized? We’ll explore the answers to such questions in this chapter, but before we do, there are a few technical distinctions you must first become aware of. In the Java programming language, the terms “field” and “variable” are both used; this is ...