Page 172 - DCAP404 _Object Oriented Programming

Unit 8: Type Conversion

The selection structure allows for decisions to be made, explains Messinger. “It has only Notes
one entry point, as do all the other structures in computer programming; but after the
decision, we can proceed in one of two independent directions.”
Somebody who thinks logically is a nice contrast to the real world, is the ‘Law of Thumb’,
as one learns in another chapter on ‘compound logic’.

And yet another chapter, which discusses loops, begins with George Eliot’s thought,
“Iteration, like friction, is likely to generate heat instead of progress.”
Hamlet’s words, “Yea, from the table of my memory I’ll wipe away all trivial fond records,”
introduce readers to `tables’. Tables are contiguous memory locations in RAM that have a
common name, explains the author. A simple example of a four-dimension table is book,
he writes, referring to chapter, page, line and column. “A common application of multi-
dimension tables is the market survey.”

Procedural programming paradigm is not the only choice, and so the book explains two
other popular ones, viz. visual or graphical user interface programming, and object-
oriented programming.
Easy read, replete with exercises and ‘enrichments’.
AIMED at ‘empowering productivity for the Java developer’, here is the third edition of
Beginning J2ME: From Novice to Professional, by Sing Li and Jonathan Knudsen.
The book is about programming “mobile phones, pagers, PDAs, and other small devices”,
and MIDP (Mobile Information Device Profile), which is part of the Java 2 Platform.

J2ME isn’t a specific piece of software or specification, explain the authors. “All it means is
Java for small devices.”
The market is expanding rapidly for two reasons: “First, developers can write code and
have it run on dozens of small devices, without change. Second, Java has important safety
features for downloadable code.”

MIDP applications are called MIDlets, rhyming with applets and servlets. “Writing MIDlets
is relatively easy for a moderately experienced Java programmer,” is an enticingly
reassuring line. Please note that “the actual development process, however, is a little
more complicated for MIDlets than it is for J2SE applications,” because of `some additional
tweaking and packaging’ required.
To make MIDlets as compact as possible, ‘obfuscator’ is used. This is a tool, “originally
designed to foil attempts to reverse engineer compiled bytecode”; it renames classes,
member variables, and methods to more compact name; removes unused classes and so
on; and inserts illegal or questionable data to confuse decompilers.

A killer application for the wireless is SMS, says the duo. “The ability to send short text
messages (up to 160 characters in most cases) between cell-phone users inexpensively is
compelling enough. The possibility to send messages directly between J2ME applications
running on cellular phones is even more exciting,” opine the authors.
A chapter is devoted to ‘Bluetooth and OBEX’. The former is “a radio connectivity
technology designed for creating Personal Area Networks (PANs)” to help you connect
things that are next to you; and the latter is short for Object Exchange, “a communication
protocol that enables applications to talk to one another easily over infrared”.
Bluetooth networks are formed ad hoc and dynamically when Bluetooth-enabled devices
come into proximity of one another, as Li and Knudsen explain. “Technically, a Bluetooth
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