Discovering Computers: Chapter 13

Discovering
Computers 2012
Your Interactive Guide
to the Digital World

Objectives Overview

Identify and discuss the
Identify and discuss the
characteristics of these
Differentiate between purpose of procedural
object-oriented
machine and assembly programming languages,
programming languages
languages and describe the features of
and program development
C and COBOL
tools

Identify the uses of other
programming languages Describe various ways to
and program development develop Web pages
tools

See Page 663 Discovering Computers 2012: Chapter 13 2
for Detailed Objectives

Objectives Overview

Identify the uses of List the six steps in the
popular multimedia program development
authoring programs life cycle

Explain the basic
Differentiate between control structures and
structured design and design tools used in
object-oriented design designing solutions to
programming problems
See Page 663 Discovering Computers 2012: Chapter 13 3
for Detailed Objectives

Computer Programs
and Programming Languages
• A computer program is a series of instructions
that directs a computer to perform tasks
– Created by a programmer using a programming
language

Pages 664 – 665 Discovering Computers 2012: Chapter 13 4
Figure 13-1

Low-Level Languages

• Machine language is
the first generation of
• Only language the
computer directly
recognizes

Page 665 Discovering Computers 2012: Chapter 13 5
Figure 13-2

Low-Level Languages

• Assembly language is the
second generation of
• Programmer writes
instructions using
symbolic instruction
codes
• A source program
contains the code to be
converted to machine
language

Figure 13-3

Procedural Languages

• In a procedural language, the programmer writes
instructions that tell the computer what to
accomplish and how to do it
– Third-generation language (3GL)

A compiler
translates an entire
program before An interpreter converts
executing it and executes one code
statement at a time

Pages 666 - 667 Discovering Computers 2012: Chapter 13 7


Figures 13-4 – 13-5


• The C programming language is used to write
many of today’s programs

Figure 13-6


• COBOL (COmmon Business-Oriented Language) is
designed for business applications, but easy to
read because of the English-like statements

Figure 13-7

Object-Oriented Programming Languages
and Program Development Tools
• An object-oriented programming (OOP) language allows
programmers the ability to reuse and modify existing
objects
• Other advantages include:
Programmers
Objects can be
create applications
reused
faster

Most program
Work well in a
development tools
RAD environment
are IDEs

• Java is an object-oriented programming language
developed by Sun Microsystems
• The Just-in-time (JIT) compiler converts the bytecode into
machine-dependent code

Figure 13-8

• The Microsoft .NET Framework allows almost any
type of program to run on the Internet or an
internal business network, as well as computers
and mobile devices
• Features include:

CLR (Common
Language Classes
Runtime)

• C++ is an extension of
the C programming
language
• C# is based on C++ and
was developed by
Microsoft
• F# combines the
benefits of an object-
oriented language with
those of a functional
language
Figure 13-9


Visual Studio is Microsoft’s suite of
program development tools
Visual C# combines
Visual Basic is the programming
based on the BASIC Visual C++ is based elements of C++
programming on C++ with an easier,
language rapid-development
environment



Figure 13-10


A visual programming language is a language that
uses a visual or graphical interface for creating all
source code

Borland’s Delphi is a powerful program
development tool that is ideal for building large-
scale enterprise and Web applications in a RAD
environment


Figure 13-11

• PowerBuilder is a
powerful program
development RAD tool
• Best suited for Web-
based, .NET, and large-
scale enterprise object-
oriented applications

Figure 13-12

Other Programming Languages
and Development Tools
• A 4GL (fourth-generation language) is a
nonprocedural language that enables users and
programmers to access data in a database
– One popular 4GL is SQL

Figure 13-13

• Classic programming languages include:
Ada ALGOL APL BASIC

Forth FORTRAN HyperTalk LISP

Logo Modula-2 Pascal PILOT

PL/1 Prolog RPG Smalltalk
Figure 13-14

• An application generator is a program that creates
source code or machine code from a specification of the
required functionality
– Often bundled as part of a DBMS

Figure 13-15

• A macro is a series of statements that instructs an
application how to complete a task
• You usually create the macro in one of two ways:
– Record the macro with a macro recorder
– Write the macro



Figure 13-16

Web Page Development

• HTML is a special
formatting language
that programmers use
to format documents
for display on the Web
• XHTML is a markup
language that allows
Web sites to be
displayed more easily
on mobile devices
Figure 13-17


• XML allows Web developers to create customized
tags and use predefined tags to display content
appropriately on various devices
– WML is a subset of XML and is used to design pages
for microbrowsers
• Two applications of XML are RSS 2.0 and ATOM



Figure 13-18


• Web browsers can execute short programs to add
interactive elements to Web pages
• To send and receive information between your computer
and a Web server, these programs use the CGI (common
gateway interface)
Scripts Applets

ActiveX
Servlets
controls


Figure 13-19


• Programmers write scripts, applets, servlets, or
ActiveX controls using a variety of languages

JavaScript Perl PHP

Rexx Tcl VBScript


Figure 13-20


Dynamic HTML (DHTML) allows Web
developers to include more graphical
interest and interactivity

• Cascading style sheets (CSS) contain the formats for how a particular
object should be displayed

Ruby on Rails (RoR) provides technologies
for developing object-oriented, database-
driven Web sites



• Web 2.0 allows Web sites to provide a means for
users to:
Allow users to
Share personal
modify Web site
information
content

Have application
software built
into the site


• Most Web 2.0 sites use APIs
– An API enables programmers to interact with an
environment such as a Web site or operating system

Figure 13-21


• Web page authoring software can create
sophisticated Web pages that include images,
video, audio, animation, and other effects
Expression
Dreamweaver
Web

SharePoint
Flash
Designer

Multimedia Program Development

• Multimedia authoring software allows
programmers to combine text, graphics,
animation, audio, and video in an interactive
presentation

ToolBook Director


Multimedia Program Development

Figure 13-22

Program Development

• Program development consists of a series of steps
programmers use to build computer programs

Figure 13-23

Step 1 – Analyze Requirements

• To initiate program development, programmer:
– Reviews the requirements
– Meets with the systems analyst and users
– Identifies input, processing, and output
• IPO chart

Figure 13-24

Step 2 – Design Solution

• Design a solution algorithm
• In structured design, the programmer typically
begins with a general design and moves toward a
more detailed design
• Programmers use a hierarchy chart to show
program modules graphically



Figure 13-25


• With object-oriented
(OO) design, the
programmer packages
the data and the
program into a single
object
– Encapsulation

Figure 13-26


• The sequence control
structure shows one or
more actions following
each other in order

Figure 13-27


• The selection control
structure tells the
program which action
to take, based on a
certain condition
– If-then-else
– Case

Figure 13-28


Figure 13-29


• The repetition control structure enables a program to
perform one or more actions repeatedly as long as a
certain condition is met

Figures 13-30 – 13-31


• A program flowchart graphically shows the logic
in a solution algorithm

Figure 13-33


• Flowcharting software makes it easy to modify
and update flowcharts
– SmartDraw
– Visio

Figure 13-34


• Pseudocode uses a
condensed form of
English to convey
program logic

Figure 13-35


• UML (Unified Modeling Language) has been
adopted as a standard notation for object
modeling and development

Figure 13-37

Step 3 – Validate Design

• Check for logic errors using test data

Develop Determine Step Repeat
various the through Compare steps for
sets of test expected the the results each set of
data result algorithm test data


Step 4 – Implement Design

• Implementation of the design includes using a
program development tool that assists the
programmer by:
– Generating or providing some or all code
– Writing the code that translates the design into a
computer program
– Creating the user interface
• Extreme programming is a strategy where
programmers immediately begin coding and testing
solutions as soon as requirements are defined


Step 5 – Test Solution

The goal of program testing is to ensure the
program runs correctly and is error free
• Errors include syntax errors and logic errors
• Debugging the program involves removing the bugs
• A beta is a program that has most or all of its
features and functionality implemented


Step 6 – Document Solution

• In documenting the solution, the programmer
performs two activities:

Review the Review all the
program code documentation


Summary

Various programming A variety of Web
languages used to development and
create computer multimedia
programs development tools

Steps in the program
development life cycle
and tools used to make
this process efficient


Discovering
Computers 2012
Your Interactive Guide
to the Digital World
Chapter 13 Complete

Discovering Computers: Chapter 13

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Discovering Computers: Chapter 13