Answers to Self-Review Questions - Java Software Solutions: Foundations of Program Design - page 737

SR 1.15 Counting the number of unique connections in Figure 1.16, there are 10

communication lines needed to fully connect a point-to-point network
of five computers. Adding a sixth computer to the network will require
that it be connected to the original five, bringing the total to 15 com-
munication lines.

SR 1.16 Having computers on a network share a communication line is cost

effective because it cuts down on the number of connections needed and
it also makes it easier to add a new computer to the network. Sharing
lines, however, can mean delays in communication if the network is
busy.

SR 1.17 The word Internet comes from the word internetworking, a concept

related to wide-area networks (WANs). An internetwork connects one
network to another. The Internet is a WAN.

SR 1.18 TCP stands for Transmission Control Protocol. IP stands for Internet

Protocol. A protocol is a set of rules that govern how two things com-
municate.

SR 1.19 Breaking down the parts of each URL:

a. duke is the name of a computer within the csc subdomain
(the Department of Computing Sciences) of the villanova.edu
domain, which represents Villanova University. The edu top-level
domain indicates that it is an educational organization. This URL
is requesting a file called examples.html from within a subdirec-
tory called jss .
b. java is the name of a computer (Web server) at the sun.com
domain, which represents Sun Microsystems, Inc. The com top-
level domain indicates that it is a commercial business. This URL
is requesting a file called index.html from within a subdirectory
called products .

1.4 The Java Programming Language
SR 1.20 The Java programming language was developed in the early 1990s by

James Gosling at Sun Microsystems. It was introduced to the public in
1995.

SR 1.21 The processing of a Java application begins with the main method.

SR 1.22 The characters “Hello” will be printed on the computer screen.

SR 1.23 The entire line of code is a comment, so there is no result.

SR 1.24 All of the identifiers shown are valid except 12345 (since an identifier

cannot begin with a digit) and black&white (since an identifier cannot