1.  2009 Pearson Education, Inc. All rights reserved. 1 1 1 Introduction to Computers, the Internet and Visual C#

2.  2009 Pearson Education, Inc. All rights reserved. 2 The chief merit of language is clearness. – Galen High thoughts must have high language. – Aristophanes Our life is frittered away with detail.... Simplify, simplify. – Henry David Thoreau

3.  2009 Pearson Education, Inc. All rights reserved. 3 My object all sublime I shall achieve in time. – W. S. Gilbert Man is still the most extra­ordinary computer of all. – John F. Kennedy

4.  2009 Pearson Education, Inc. All rights reserved. OBJECTIVES In this chapter you will learn: Basic hardware and software concepts. The different types of programming languages. Which programming languages are most widely used. The history of the Visual C# programming language. Some basics of object technology. 4

5.  2009 Pearson Education, Inc. All rights reserved. Chapter 1 – Introduction to C# 5 Machine Languages, Assembly Languages and High-Level Languages Programmers write instructions in various programming languages. Computer languages can be divided into three general types: Machine languages Assembly languages High-level languages

6.  2009 Pearson Education, Inc. All rights reserved. Machine Languages, Assembly Languages and High-Level Languages (Cont.) 6 A computer can directly understand only its own machine language. Machine languages generally consist of streams of numbers (ultimately reduced to binary 1s and 0s). Machine-language programs are nearly incomprehensible to humans: +1300042774 +1400593419 +1200274027

7.  2009 Pearson Education, Inc. All rights reserved. Machine Languages, Assembly Languages and High-Level Languages (Cont.) Machine-language programming proved to be slow and error prone. English-like abbreviations form the basis of assembly languages. Assemblers convert assembly-language programs to machine language. LOAD BASEPAY ADD OVERPAY STORE GROSSPAY Computers cannot understand assembly-language code until it is translated into machine language. 7

8.  2009 Pearson Education, Inc. All rights reserved. 1.7 Machine Languages, Assembly Languages and High-Level Languages (Cont.) To speed up the programming process, high-level languages were developed. Compilers convert high-level-language programs into machine language. High-level languages look almost like everyday English: X= Y+ Z 8

9.  2009 Pearson Education, Inc. All rights reserved. 1.7 Machine Languages, Assembly Languages and High-Level Languages (Cont.) 9 Fig. 1.1 | Comparing machine, assembly and high-level languages.

10.  2009 Pearson Education, Inc. All rights reserved. C, C++, Visual Basic.NET and Java C – Developed by Dennis Ritchie - Evolved from the B language at Bell Labs - Added data type features – Gained recognition as language of UNIX – Now a widely used language - Available on most computers - Language of most major operating systems - Led to development of C++ 10

11.  2009 Pearson Education, Inc. All rights reserved. C, C++, Visual Basic.NET and Java (II) C++ – Developed by Bjarne Stroustrup at Bell Labs (1980s) – Extension of C - Uses elements from Simula 67 Simulation programming language - Provides features to “spruce up” C - Provides Object-oriented technology Hybrid language  Possible to program structurally  Possible to program with object-oriented technology  Possible to use both 11

12.  2009 Pearson Education, Inc. All rights reserved. C, C++, Visual Basic.NET and Java (III) Object-Oriented Programming – Uses objects - Reusable software components - Modeled after items in the real world – More productive than structured programming – Easier to understand, correct and modify 12

13.  2009 Pearson Education, Inc. All rights reserved. C, C++, Visual Basic.NET and Java (IV) Visual Basic. NET – Based from BASIC (mid 1960s) - Beginners All-Purpose Symbolic Instruction Code - Implemented by Bill Gates at Microsoft – Evolved to Visual Basic - Resulting from Windows GUI (late 1980s early 1990s) Graphical User Interface - Included capabilities such as object oriented programming, error handling and GUI creation – Evolved to.NET - Allows access to.NET libraries - Improved object oriented programming 13

14.  2009 Pearson Education, Inc. All rights reserved. C, C++, Visual Basic.NET and Java (V) Java – Sun Microsystems corporate research project (1991) - Code-named Green – Based on C and C++ – Intended for intelligent consumer-electronic devices - Lack of popularity almost causes cancellation – Sudden popularity of WWW provides new potential - Java capable of dynamic content Animated and interactive content - Grabbed attention of business community – Now very widely used - Enhance functionality of WWW servers - Provide applications for consumer devices 14

15.  2009 Pearson Education, Inc. All rights reserved. C# – Developed at Microsoft by a team led by Anders Hejlsberg and Scott Wiltamuth – Event driven, object oriented, visual programming language – Based from C, C++ and Java – Incorporated into.NET platform - Web based applications can be distributed Devices and desktop computers - Programs that can be accessed by anyone through any device - Allows communicating with different computer languages – Integrated Design Environment (IDE) - Makes programming and debugging fast and easy - Rapid Application Development (RAD) 15

16.  2009 Pearson Education, Inc. All rights reserved. C# (II) SOAP – Simple Object Access Protocol – Allows the communicating of languages - Any.NET language – Helps to share program “chunks” over the internet 16

17.  2009 Pearson Education, Inc. All rights reserved. Key Software Trend: Object Technology What is Object Technology? – Packaging scheme for creating software units - Units are objects Any noun can be represented as an object  Date object, time object, car object Have properties  Size, color, weight Perform actions  Moving, sleeping, drawing Defined in classes  Specify general format  Provide specific attributes and behaviors 17

18.  2009 Pearson Education, Inc. All rights reserved. Key Software Trend: Object Technology (II) Object-Oriented programming – Based on nouns - Reflects way world is perceived – Advantages over structured programming - More natural process Results in better productivity - Classes provide reusability Microsoft Foundation Classes (MFC) - Easier to maintain Programs more understandable Focus on behaviors and interactions Less attention to details 18

19.  2009 Pearson Education, Inc. All rights reserved. Introduction to Microsoft.NET.NET initiative – Introduced by Microsoft (June 2000) - Vision for embracing the Internet in software development – Independence from specific language or platform - Applications developed in any.NET compatible language Visual Basic.NET, Visual C++.NET, C# and more - Programmers can contribute to applications using the language in which they are most competent – Architecture capable of existing on multiple platforms – New program development process - Provides increased productivity 19

20.  2009 Pearson Education, Inc. All rights reserved. Introduction to Microsoft.NET (II) Key components of.NET – Web services - Applications used over the Internet – Software reusability - Web services provide solutions for wide variety of companies Cheaper than developing one-time solutions that can’t be reused Single applications perform all operations for a company via various Web services  Manage taxes, bills, investments and more - Pre-packaged components Make application development quicker and easier Developers no longer need to be concerned with details of components 20

21.  2009 Pearson Education, Inc. All rights reserved. Introduction to Microsoft.NET (III) Keys to interaction – XML and SOAP - “Glue” that combines various Web services to form applications XML gives meaning to data SOAP allows communication to occur easily 21

22.  2009 Pearson Education, Inc. All rights reserved. Introduction to Microsoft.NET (IV) Other concepts – Universal data access - Eliminates need to synchronize files Updating multiple copies of same file to the most recent - Data resides at one central location Accessible by anyone with connection and proper authorization - Data formatted appropriately for display on various devices Same document seen on PC, PDA, cell phone and other devices – Additional information available at Microsoft Web site www.microsoft.com/net www.microsoft.com/net 22