Chapter 1: Review Exercise Solutions
R1.1
A well-designed computer program is easy to use without any special knowledge. For
example, most people can learn to navigate webpages with only a few minutes of
practice. On the other hand, programming a computer requires special knowledge about
what the computer can fundamentally do and how you would communicate with it
through a programming language.
R1.2
Typically program code is stored on a hard disk, CD/DVD disc, or in some other central
location across a network. User data is often more likely to be stored on a local hard
disk, although it can also be stored on a network or even a CD/DVD for backup storage.
R1.3
The monitor, speakers, and printer serve as the primary devices to give information to the
user. The keyboard and mouse are the primary devices that take user input.
R1.4
,It's very likely your cell phone is a programmable computer. If you can take pictures,
send email/text messages, and/or surf the web with your phone, it is a programmable
computer. If your cell phone can only send and receive phone calls, it is probably a
single-function device.
R1.5
One advantage of Java over machine code is that Java statements are independent of the
machine (computer) they are being executed on; machine code statements differ from one
type of machine to the next. Another advantage of Java is that it is much more readable
and understandable (by humans) than machine code.
R1.6
a) Solutions here will vary based on user and IDE preference. On a UNIX-based system
using the Eclipse IDE you may see a path like
/home/nancy/JFE/src
While on a Microsoft Windows machine you might find a directory like:
C:\Users\nancy\Documents\JFE\src
b) Again, solutions can vary. On Unix using Eclipse you might see:
/home/nancy/JFE/bin
, A Microsoft Windows machine might be:
C:\Users\nancy\Documents\JFE\bin
c) The answer to this question is dependent on the type of operating system and
version of Java. On a Unix based system using Java 1.6 you might find rt.jar here:
/usr/lib/jvm/java-6-sun-1.6.0.13/jre/lib/rt.jar
While on a Microsoft Windows platform you might find it here:
C:\Program Files\Java\jdk1.6.0_10\jre
R1.7
The program prints the following:
39 + 3
42
Java interprets the statement "39 + 3" as a string and thus prints out the literal
characters 39 + 3. Java interprets the second statement 39 + 3 as an operation between
two numbers, so it first calculates the value 39 + 3 = 42 then prints out the result 42.
R1.8
HelloWorld
, Because there are no spaces after the System.out.print("Hello"); the next line prints
World directly after Hello is printed.
R1.9
Java interprets the comma in the println method to mean that two strings are passed to
println. It’s likely the programmer meant to do this:
System.out.print("Hello, World!");
R1.10
This version omits a semicolon after the println statement and omits a curly brace to
close the class:
public class HelloPrinter1
{
public static void main(String[] args)
{
System.out.println("Hello, World!")
}
R1.1
A well-designed computer program is easy to use without any special knowledge. For
example, most people can learn to navigate webpages with only a few minutes of
practice. On the other hand, programming a computer requires special knowledge about
what the computer can fundamentally do and how you would communicate with it
through a programming language.
R1.2
Typically program code is stored on a hard disk, CD/DVD disc, or in some other central
location across a network. User data is often more likely to be stored on a local hard
disk, although it can also be stored on a network or even a CD/DVD for backup storage.
R1.3
The monitor, speakers, and printer serve as the primary devices to give information to the
user. The keyboard and mouse are the primary devices that take user input.
R1.4
,It's very likely your cell phone is a programmable computer. If you can take pictures,
send email/text messages, and/or surf the web with your phone, it is a programmable
computer. If your cell phone can only send and receive phone calls, it is probably a
single-function device.
R1.5
One advantage of Java over machine code is that Java statements are independent of the
machine (computer) they are being executed on; machine code statements differ from one
type of machine to the next. Another advantage of Java is that it is much more readable
and understandable (by humans) than machine code.
R1.6
a) Solutions here will vary based on user and IDE preference. On a UNIX-based system
using the Eclipse IDE you may see a path like
/home/nancy/JFE/src
While on a Microsoft Windows machine you might find a directory like:
C:\Users\nancy\Documents\JFE\src
b) Again, solutions can vary. On Unix using Eclipse you might see:
/home/nancy/JFE/bin
, A Microsoft Windows machine might be:
C:\Users\nancy\Documents\JFE\bin
c) The answer to this question is dependent on the type of operating system and
version of Java. On a Unix based system using Java 1.6 you might find rt.jar here:
/usr/lib/jvm/java-6-sun-1.6.0.13/jre/lib/rt.jar
While on a Microsoft Windows platform you might find it here:
C:\Program Files\Java\jdk1.6.0_10\jre
R1.7
The program prints the following:
39 + 3
42
Java interprets the statement "39 + 3" as a string and thus prints out the literal
characters 39 + 3. Java interprets the second statement 39 + 3 as an operation between
two numbers, so it first calculates the value 39 + 3 = 42 then prints out the result 42.
R1.8
HelloWorld
, Because there are no spaces after the System.out.print("Hello"); the next line prints
World directly after Hello is printed.
R1.9
Java interprets the comma in the println method to mean that two strings are passed to
println. It’s likely the programmer meant to do this:
System.out.print("Hello, World!");
R1.10
This version omits a semicolon after the println statement and omits a curly brace to
close the class:
public class HelloPrinter1
{
public static void main(String[] args)
{
System.out.println("Hello, World!")
}
