2001 Deitel & Associates, Inc. All rights reserved. 1 Chapter 1 – Introduction to Computers, the Internet and the Web Outline 1.1Introduction 1.2The

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2001 Deitel & Associates, Inc. All rights reserved.

Chapter 1 – Introduction toComputers, the Internet and the Web

Outline1.1 Introduction1.2 The Future of Computing1.3 e-Business and e-Commerce1.4 What is a Computer?1.5 Types of Programming Languages1.6 Other High-Level Languages1.7 Structured Programming1.8 History of the Internet1.9 Personal Computing, Distributed Computing and

Client/Server Computing1.10 History of the World Wide Web1.11 Hardware Trends1.12 The Key Software Trend: Object Technology1.13 JavaScript: Object-Based Scripting for the Web1.14 Browser Portability1.15 Evolution of the How to Program Series: C and C++

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Chapter 1 – Introduction toComputers, the Internet and the Web

Outline1.16 Java and Java How to Program1.17 Internet and World Wide Web How to Program1.18 e-Business and e-Commerce How to Program1.19 Dynamic HTML

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1.1 Introduction

• We will learn– Structured programming and proper programming

techniques

• This course is appropriate for– Novices with little or no programming experience

– Experienced professionals building substantial information systems

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1.2 The Future of Computing

• Future of Computers– Use increasing dramatically

– Costs decreasing

– Explosion of Internet and World Wide Web• Multimedia content

• Increasing bandwidth

• Magazines and books already going online

• Easy international communication

– Could replace TV, radio and phone

– Helping the disabled

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1.3 e-Business and e-Commerce

• e-Business– Provides products and services 24 hours a day

– Provides unlimited inventory

– Allows consumer to comparison shop

– Essential to business success

– Replacing “brick and mortar” stores

– Personalize user’s experience

• New business models introduced by Web– eBay

• Online auctions

– Priceline.com• Customers name own price

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1.3 e-Business and e-Commerce

• Consequences of Internet and Web– Privacy invasion

• One of the risks of Internet

• Personal information on the Web

• Tracking of Web movement

• Credit card security

– Piracy of intellectual property• Copyright infringement

• MP3

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1.4 What is a Computer?

• Computer – Device capable of performing computations and

making logical decisions

– Computers process data under the control of sets of instructions called computer programs

• Hardware – Various devices comprising a computer

– Keyboard, screen, mouse, disks, memory, CD-ROM, and processing units

• Software – Programs that run on a computer

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1.5 Types of Programming Languages

• Three types of programming languages1. Machine languages

• Strings of numbers giving machine specific instructions

• Example:

+1300042774

+1400593419

+1200274027

2. Assembly languages• English-like abbreviations representing elementary computer

operations (translated via assemblers)

• Example:

LOAD BASEPAY

ADD OVERPAY

STORE GROSSPAY

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1.5 Types of Programming Languages

3. High-level languages• Codes similar to everyday English

• Use mathematical notations (translated via compilers)

• Example:

grossPay = basePay + overTimePay

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1.6 Other High-level Languages

• Other high-level languages– FORTRAN

• Used for scientific and engineering applications

– COBOL • Used to manipulate large amounts of data

– Pascal • Intended for academic use

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1.7 Structured Programming

• Structured programming – Disciplined approach to writing programs

– Clear, easy to test and debug and easy to modify

• Multitasking– Specifying that many activities run in parallel

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1.8 History of the Internet

• The Internet enables– Quick and easy communication via e-mail– International networking of computers

• Packet switching– The transfer of digital data via small packets– Allows multiple users to send and receive data

simultaneously

• No centralized control– If one part of the Internet fails, other parts can still

operate

• Bandwidth – Information carrying capacity of communications lines

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1.9 Personal Computing, Distributed Computing, and Client/Server

Computing• Personal computers

– Economical enough for individual

• Distributed computing – Computing distributed over networks

• Client/server computing– Sharing of information across computer networks

between file servers and clients (personal computers)

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1.10 History of the World Wide Web

• WWW– Allows computer users to locate and view multimedia-

based documents

– Introduced in 1990 by Tim Berners-Lee

• Internet today– Mixes computing and communications technologies

– Makes information constantly and instantly available to anyone with a connection

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1.11 Hardware Trends

• Improving technologies– Internet community thrives on improvements of

• Hardware

• Software

• Communications

– Cost of products and services • Consistently dropping over the decades

– Computer capacity and speed • Doubles every two years (on average)

– Microprocessor chip• Laid groundwork in late 1970s and 1980s for productivity

improvements of the 1990s

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1.12 The Key Software Trend: Object Technology

• Objects – Reusable software components that model items in the

real world

– Meaningful software units• Date objects, time objects, paycheck objects, invoice objects,

audio objects, video objects, file objects, record objects, etc.

• Any noun can be represented as an object

– More understandable, better organized, and easier to maintain than procedural programming

– Favor modularity

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1.13 JavaScript: Object-BasedScripting for the Web

• JavaScript– Attractive package for advancing level of programming

language education

– Object-based language

– Supports proper software engineering techniques

– Free for download in today’s most popular Web browsers

• Attractive to colleges

• Bug fixes and new versions easily obtained

– Powerful scripting language• Portable

• Programs execute interpretively on client machines

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1.14 Browser Portability

• Browser portability– Great challenge

• Great diversity of client browsers in use

• Many different platforms also in use

• Difficult to– Know capabilities and features of all browsers and

platforms in use

– Find correct mix between absolute portability, complexity and usability of features

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1.15Evolution of the How to Program Series: C++ and C++

• C– Wasn’t used for teaching because of Pascal

• Used in business and in operating systems

• C How to Program began teaching C to university students

– Portable across many platforms

• C++– Extension of C

– Provides capabilities for object-oriented programming

– Very widely used in industry• Lead to writing of C++ How to Program

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1.16 Java and Java How to Program

• Java is used to – Create Web pages with dynamic and interactive content

– Develop large-scale enterprise applications

– Enhance the functionality of Web servers

– Provide applications for consumer devices (such as cell phones, pagers and personal digital assistants)

• Java How to Program – Closely followed the development of Java by Sun

– Teaches first-year programming students the essentials of graphics, images, animation, audio, video, database, networking, multithreading and collaborative computing

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1.17 Internet and World Wide WebHow to Program

• Internet and World Wide Web How to Program– Followed the Internet boom

– Focuses on enhanced capabilities of the Web• Still provides a solid treatment of programming principles

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1.18 e-Business and e-CommerceHow to Program

• e-Business and e-Commerce How to Program:– Step beyond Internet and World Wide Web How to

Program

– Explicitly teaches programming for e-Business and e-commerce

– Firm grounding for conducting business on-line

– Computer programming and basic principles of computer science

– JavaScript primary programming language

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1.19 Dynamic HTML

• DHTML– Two versions

• Microsoft

• Netscape

– Consists of number of technologies freely available for download

– Used for developing high-performance, Web-based applications

• Much of application’s work performed directly on client rather then on server or Internet

Documents

2001 Deitel & Associates, Inc. All rights reserved. 1 Chapter 1 – Introduction to Computers, the Internet and the Web Outline 1.1Introduction 1.2The