Discovering Computers 2012Chapter 13Computer Programs and Programming Languages

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Discovering

Computers 2012 Chapter 13

Computer Programs and Programming Languages

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Objectives Overview

Differentiate between machine and assembly

languages

Differentiate between machine and assembly

languages

Identify and discuss the purpose of procedural programming languages, and describe the features of

C and COBOL

Identify and discuss the purpose of procedural programming languages, and describe the features of

C and COBOL

Identify and discuss the characteristics of these

object-oriented programming languages and program development

tools

Identify and discuss the characteristics of these

object-oriented programming languages and program development

tools

Identify the uses of other programming languages and program development

tools

Identify the uses of other programming languages and program development

tools

Describe various ways to develop Web pages Describe various ways to

develop Web pages

Discovering Computers 2012: Chapter 13 2

See Page 663

for Detailed Objectives

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Objectives Overview

Identify the uses of popular multimedia authoring programs

List the six steps in the program development

life cycle

List the six steps in the program development

life cycle

Differentiate between structured design and Differentiate between structured design and

Explain the basic control structures and

design tools used in Explain the basic control structures and

design tools used in

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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 Figure 13-1

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Low-Level Languages

• Machine language is the first generation of programming languages

• Only language the computer directly recognizes

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Low-Level Languages

• Assembly language is the second generation of

programming languages

• Programmer writes instructions using

symbolic instruction codes

• A source program contains the code to be converted to machine language

Pages 665 – 666 Figure 13-3

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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

A compiler

translates an entire

program before An interpreter converts An interpreter converts

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Discovering Computers 2012: Chapter 13 8 Page 667

Figures 13-4 – 13-5

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Procedural Languages

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Procedural Languages

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

Page 668 Figure 13-6

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Procedural Languages

• COBOL (COmmon Business-Oriented Language) is designed for business applications, but easy to

read because of the English-like statements

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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:

Page 669

Objects can be reused

Programmers create applications

faster

Programmers create applications

faster

Work well in a RAD environment

Most program development tools

are IDEs Most program development tools

are IDEs

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Object-Oriented Programming Languages and Program Development Tools

• Java is an object-oriented programming language developed by Sun Microsystems

• The Just-in-time (JIT) compiler converts the bytecode into machine-dependent code

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Object-Oriented Programming Languages and Program Development Tools

• 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:

Page 670

CLR (Common Language

Runtime)

CLR (Common Language

Runtime)

Classes Classes

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Object-Oriented Programming Languages and Program Development Tools

• 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

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Object-Oriented Programming Languages and Program Development Tools

Visual Studio is Microsoft’s suite of program development tools

Visual Basic is based on the BASIC

programming language Visual Basic is based on the BASIC

programming language

Visual C++ is based on C++

Visual C# combines the programming

elements of C++

with an easier, rapid-development

environment

Visual C# combines the programming

elements of C++

with an easier, rapid-development

environment

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Object-Oriented Programming Languages and Program Development Tools

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

Borland’s Delphi is a powerful program

development tool that is ideal for building large- scale enterprise and Web applications in a RAD environment

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Object-Oriented Programming Languages and Program Development Tools

• PowerBuilder is a powerful program

development RAD tool

• Best suited for Web- based, .NET, and large- scale enterprise object- oriented applications

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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

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Other Programming Languages and Development Tools

• Classic programming languages include:

AdaAda ALGOLALGOL APLAPL BASICBASIC

Forth

Forth FORTRANFORTRAN HyperTalkHyperTalk LISPLISP

LogoLogo Modula-2Modula-2 PascalPascal PILOTPILOT

PL/1PL/1 PrologProlog RPGRPG SmalltalkSmalltalk

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Other Programming Languages and Development Tools

• 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

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Other Programming Languages and Development Tools

• 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

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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

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Web Page Development

• 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

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Figure 13-18

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Web Page Development

• 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

Scripts Applets Applets

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Figure 13-19

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Web Page Development

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

JavaScript

JavaScript Perl Perl PHP PHP

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Web Page Development

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Web Page Development

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

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Web Page Development

• Web 2.0 allows Web sites to provide a means for users to:

Page 684

Share personal information Share personal

information

Allow users to modify Web site

content

Allow users to modify Web site

content

Have application software built

into the site

Have application software built

into the site

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Web Page Development

• Most Web 2.0 sites use APIs

– An API enables programmers to interact with an

environment such as a Web site or operating system

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Web Page Development

• Web page authoring software can create

sophisticated Web pages that include images, video, audio, animation, and other effects

Page 685

Dreamweaver

Dreamweaver Expression Web

Expression Web

Flash

Flash SharePoint Designer SharePoint

Designer

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Multimedia Program Development

• Multimedia authoring software allows programmers to combine text, graphics,

animation, audio, and video in an interactive presentation

ToolBook

ToolBook DirectorDirector

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Figure 13-22

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Program Development

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

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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

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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

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Step 2 – Design Solution

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Step 2 – Design Solution

• With object-oriented (OO) design, the

programmer packages the data and the

program into a single object

– Encapsulation

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Step 2 – Design Solution

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

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Step 2 – Design Solution

• The selection control structure tells the

program which action to take, based on a certain condition

– If-then-else – Case

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Step 2 – Design Solution

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Step 2 – Design Solution

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

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Step 2 – Design Solution

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

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Step 2 – Design Solution

• Flowcharting software makes it easy to modify and update flowcharts

– SmartDraw – Visio

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Step 2 – Design Solution

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

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Step 2 – Design Solution

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

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Step 3 – Validate Design

• Check for logic errors using test data

Pages 693 - 694

Develop various sets of test

data Develop

various sets of test

data

Determine the expected

result Determine

the expected

result

Step through

the algorithm

Step through

the algorithm

Compare the results Compare the results

Repeat steps for each set of

test data Repeat steps for each set of

test data

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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

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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

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Step 6 – Document Solution

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

Review the program code

Review all the documentation Review all the documentation

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Video: Electronic Arts Going Mobile

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Summary

Various programming languages used to

create computer programs

Various programming languages used to

create computer programs

A variety of Web development and

multimedia

development tools A variety of Web development and

multimedia

development tools

Steps in the program development life cycle

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Your Interactive Guide to the Digital World

Discovering

Computers 2012 Chapter 13

Computer Programs and Programming Languages

Chapter 13 Complete