Answers to Self Tests - Java: A Beginner's Guide - page 827

A class is a logical abstraction that describes the form and behavior of an object. An
object is a physical instance of the class.
2 . How is a class defined?
A class is defined by using the keyword class . Inside the class statement, you specify
the code and data that comprise the class.
3 . What does each object have its own copy of?
Each object of a class has its own copy of the class' instance variables.
4 . Using two separate statements, show how to declare an object called counter of a
class called MyCounter .
5 . Show how a method called myMeth( ) is declared if it has a return type of double
and has two int parameters called a and b .
6 . How must a method return if it returns a value?
A method that returns a value must return via the return statement, passing back the
return value in the process.
7 . What name does a constructor have?
A constructor has the same name as its class.
8 . What does new do?
The new operator allocates memory for an object and initializes it using the object's
constructor.
9 . What is garbage collection and how does it work? What is finalize( ) ?
Garbage collection is the mechanism that recycles unused objects so that their
memory can be reused. An object's finalize( ) method is called just prior to an object
being recycled.
10 . What is this ?
The this keyword is a reference to the object on which a method is invoked. It is
automatically passed to a method.
11 . Can a constructor have one or more parameters?