2.22 Jb0200r: review

Revised: Mon Mar 28 13:31:46 CDT 2016

This page is included in the following Books:

• Programming Fundamentals with Java
• Object-Oriented Programming (OOP) with Java

Table of contents

• Preface
• Questions
  • 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39
• Listings
• Answers
• Miscellaneous

Preface

This module contains review questions and answers keyed to the module titled Jb0200: Java OOP: Variables .

The questions and the answers are connected by hyperlinks to make it easy for you to navigate from the question to the answer and back again.

Questions

Question 1 .

Write a Java application that reads characters from the keyboard until encountering the # character. Echo each character to the screen as it is read.Terminate the program when the user enters the # character.

Answer 1

Question 2

What is the common name for the Java program element that is used to contain data that changes during the execution of the program?

Answer 2

Question 3

What must you do to make a variable available for use in a Java program?

Answer 3

Question 4

True or false? In Java, you are required to initialize the value of all variables when they are declared.

Answer 4

Question 5

Show the proper syntax for declaring two variables and initializing one of them using a single Java statement.

Answer 5

Question 6

True or false? The Java compiler will accept statements with type mismatches provided that a suitable type conversion can be implemented by the compiler atcompile time.

Answer 6

Question 7

Show the proper syntax for the declaration of a variable of type String[] in the argument list of the main method of a Java program and explain its purpose.

Answer 7

Question 8

Describe the purpose of the type definition in Java.

Answer 8

Question 9

True or false? Variables of type int can contain either signed or unsigned values.

Answer 9

Question 10

What is the important characteristic of type definitions in Java that strongly supports the concept of platform independence of compiled Java programs?

Answer 10

Question 11

What are the two major categories of types in Java?

Answer 11

Question 12

What is the maximum number of values that can be stored in a variable of a primitive type in Java?

Answer 12

Question 13

List the primitive types in Java.

Answer 13

Question 14

True or false? Java stores variables of type char according to the 8-bit extended ASCII table.

Answer 14

Question 15

True or false? In Java, the name of a primitive variable evaluates to the value stored in the variable.

Answer 15

Question 16

True or false? Variables of primitive data types in Java are true objects.

Answer 16

Question 17

Why do we care that variables of primitive types are not true objects?

Answer 17

Question 18

What is the name of the mechanism commonly used to convert variables of primitive types to true objects?

Answer 18

Question 19

How can you tell the difference between a primitive type and a wrapper for the primitive type when the two are spelled the same?