Warren Sheaffer's Profile

However, declaring a variable does not create an object!
This is an important point, which is related to this Very Important Fact:

5.1.3  Getters and Setters

When writing new classes, it's a good idea to pay attention to the issue
of access control. Recall that making a member of a class public
makes it accessible from anywhere, including from other classes. On the
other hand, a private member can only be used in the class
where it is defined.

In the opinion of many programmers, almost all member variables should
be declared private. This gives you complete control over what
can be done with the variable. Even if the variable itself is private,
you can allow other classes to find out what its value is by providing
a public accessor method that returns the
value of the variable. For example, if your class contains a private
member variable, title, of type String, you
can provide a method

public String getTitle() {
    return title;
}

that returns the value of title. By convention, the name of
an accessor method for a variable is obtained by capitalizing the name of variable and
adding "get" in front of the name. So, for the variable title, we get
an accessor method named "get" + "Title", or getTitle().
Because of this naming convention, accessor methods are more often referred to
as getter methods. A getter method provides "read access" to
a variable.

You might also want to allow "write access" to a private variable.
That is, you might want to make it possible for other classes to specify a new value
for the variable. This is done with a setter method. (If you don't
like simple, Anglo-Saxon words, you can use the fancier term mutator method.)
The name of a setter method should consist of "set" followed by a capitalized copy of
the variable's name, and it should have a parameter with the same type as the
variable. A setter method for the variable title could be written