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Transcript of 2001 Deitel & Associates, Inc. All rights reserved. 1 Chapter 1 – Introduction to Computers, the...
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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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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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2001 Deitel & Associates, Inc. All rights reserved.
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