Discovering Computers - Chapter 13: Programming Languages and Program Development

Discovering Computers - Chapter 13: Programming Languages and Program Development present Computer Programs and Programming Languages, Low-Level Languages, Procedural Languages, Object-Oriented Programming Languages.

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Chapter 13 Programming Languages and

Program Development

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Chapter 13 Objectives

Next

Describe various ways to develop Web pages including HTML, scripting languages, DHTML, XML, WML, and Web page

authoring software

Describe various ways to develop Web pages including HTML, scripting languages, DHTML, XML, WML, and Web page

authoring software

Differentiate between machine

and assembly languages

Differentiate between machine

and assembly languages

Identify and discuss the purpose of

procedural programming languages

Identify and discuss the purpose of

procedural programming languages

Identify and discuss the characteristics of

object-oriented programming languages

Identify and discuss the characteristics of

object-oriented programming languages

Discuss the advantages and uses of visual

programming languages

Discuss the advantages and uses of visual

programming languages

Identify the uses of other programming

languages and other program development

tools

Identify the uses of other programming

languages and other program development

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Computer Programs and Programming Languages

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Computer Programs and Programming Languages

What are low-level languages and high-level languages?

High-level language

Low-level language

Machine-dependent

runs only on one type of computer

Machine-dependent

runs only on one type of computer Often machine-independent

can run on many different types of computers

Often machine-independent

can run on many different types of computers Machine and assembly languages

are low-level Machine and assembly languages

are low-level

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combination of numbers and

letters that represent binary

digits

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abbreviations and codes

 Source program contains

code to be converted to

machine language

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and how to do it

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Procedural Languages

 Designed for business applications

 English-like statements make code easy to read, write,

and maintain

Business-Oriented Language

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navigation, then click

COBOL below Chapter 13

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Object-Oriented Programming Languages

What is an object-oriented programming (OOP) language ?

Event-driven—

checks for and responds

to set of events

C++ and Java are complete object-oriented languages

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Java below Chapter 13

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 Includes all elements of C, plus additional features

for working with object-oriented concepts

 Used to develop

database and Web applications

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C++ below Chapter 13

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 Object-oriented programming language based on C++

 Accepted as a standard for Web applications and

XML-based Web services

 Uses a JIT compiler

 Resulting code is called Microsoft Intermediate

Language (MSIL)

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Programmer writes and implements program in segments

environment

Sometimes called

fifth-generation language

Provides visual or graphical interface for creating source code

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RAD below Chapter 13

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 .NET is set of technologies that allows program to run on Internet

 Comprised of Visual Basic 2005 , Visual C++ 2005 , Visual C# 2005 , and Visual

Step 4. The programmer tests the application.

Step 3. The programmer writes code

to define the action of each command button.

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Visual Studio 2005

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 Powerful visual programming tool

 Ideal for large-scale enterprise and Web applications

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 Another powerful visual programming tool

 Best suited for Web-based and large-scale

object-oriented applications

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Nonprocedural Languages

and Program Development Tools

development tools?

Nonprocedural Language

The programmer writes like instructions or interacts with

English-a visuEnglish-al environment to retrieve data from files or a database

Nonprocedural Language

The programmer writes like instructions or interacts with

English-a visuEnglish-al environment to retrieve data from files or a database

Program Development

Tools

User-friendly programs designed to assist both programmers and users in creating programs

Program Development

Tools

User-friendly programs designed to assist both programmers and users in creating programs

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Other Programming Languages

 Nonprocedural language used for generating reports,

performing computations, and updating files

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 Nonprocedural language that allows access to data in

database

 Popular 4GL is SQL , query language that allows users to

manage data in relational DBMS

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What are other available programming languages?

ALGOL

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Other Program Development Tools

 Program that creates source code or machine code from

specification

 Consists of report writer, form, and menu generator

 Form provides areas for entering data

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Other Program Development Tools

What is Visual Basic for Applications (VBA)?

 Macro—series of statements used to automate tasks

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Macros below Chapter 13

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Web Page Development

 Used to create Web pages

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HTML below Chapter 13

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How are special effects and interactive elements added

to a Web page?

Counter

tracks number of visitors to Web site

Image map

graphic image that points to URL

collects data from visitors

to Web site

Servlet

applet that runs on server

ActiveX control

small program that runs on client

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What is the common gateway interface (CGI)?

 Communications standard that defines how Web server

communicates with outside sources

Step 3 When the user submits a request, it is sent to the CGI program The CGI program contacts the

database and requests information for the user In this case, it looks for a

movie titled The Wizard of Oz.

 CGI script—program that manages sending and receiving across CGI

Step 2 The Webmaster creates a link between the CGI program and Web page When a user displays the Web page, the CGI program

automatically starts.

Step 4 The CGI program receives information from the database, assembles

it in an HTML format, and sends it

to the user’s Web browser.

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What is a scripting language?

 VBScript (Visual Basic,

Scripting Edition)— adds intelligence and

interactivity to Web page

 Perl (Practical Extraction

and Report Language)—

has powerful text processing capabilities

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Scripting Languages

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XHTML (Extensible HTML)

enables Web sites to be displayed more easily on microbrowsers

XML (Extensible Markup Language)

allows developers to create customized tags

WML (Wireless Markup Language)

allows developers to design pages specifically for microbrowsers

Includes features of HTML

and XML

Many PDAs and smart phones use WML as their markup language

Server sends entire record to client, enabling client to do much of processing without going back to server

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XML below

Chapter 13

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FrontPage 2003

Flash MX

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Multimedia Program Development

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The Program Development Cycle

 Steps programmers use to build computer programs

 Programming

team—Group of programmers working on program

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Step 1 — Analyze Requirements

What is involved in analyzing the requirements?

1. Review requirements

2. Meet with systems analyst and users

3. Identify input, output, processing, and data

components

Identifies program’s inputs, outputs, and

processing steps

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Programmer begins with general design and moves toward

detailed design

Step 2 — Design Solution

What is involved in designing the solution?

Object-oriented

design

Structured design , sometimes called top-down design

Two approaches

Devise solution algorithm, step-by-step procedure to solve problem

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 Shows program modules graphically

 Also called structure chart

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 Programmer packages data and

procedure into single unit, an object

 Objects are grouped into classes

 Class diagram represents hierarchical

relationships of classes graphically

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Object-Oriented Design

below Chapter 13

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What is a sequence control structure?

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What is a selection control structure?

action to take, based

on a certain condition

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What is a case control structure?

 Yields one of three or more possibilities

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What is a repetition control structure?

 Do-until control

structure—repeats

until condition is true

Do-While Control Structure Do-Until Control Structure

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What is a program flowchart?

 Graphically shows logic

in solution algorithm

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 Used by programmers to develop flowcharts

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Flowcharting Software

below Chapter 13

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Step 3 — Validate Design

What is involved in validating the design?

Check program design for accuracy

Logic error design flaw that causes inaccurate results

Test data sample data that mimics real data that program will process

Programmer checks logic for correctness and attempts to uncover

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Step 4 — Implement Design

 Writing the code that translates the design into a program

 Syntax—rules that specify how to write instructions

 Comments—program documentation

 Extreme programming (XP)—coding and testing as soon as

requirements are defined

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Extreme Programming

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Step 5 — Test Solution

What is involved in testing the solution?

Ensure program runs correctly

and is error free

Debugging —locating and correcting syntax and logic

errors, or bugs

Test copy of program, called beta , sometimes used to find bugs

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Step 6 — Document Solution

What is involved in documenting the solution?

 Programmer performs two activities

Reviews program code—removes dead code, program instructions that program never executes

Reviews documentation Reviews documentation

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Summary of Programming Languages and Program Development

Various programming languages

used to write and develop

computer programs

Various programming languages

used to write and develop

computer programs

The program development

cycle and the tools used to make

this process efficient

The program development

cycle and the tools used to make

this process efficient

Web development and multimedia

development tools

Web development and multimedia

development tools

Chapter 13 Complete

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