1. Introduction to Computer and Programing Thanachat Thanomkulabut

2. Outline 2  Introduction to computer  Programming Languages  C# Language Overview

3. Definition of Computer 3  Devices for performing computations at high speeds with great accuracy  A machine that can be programmed to manipulate symbols  Can quickly store and retrieve large amounts of data.  Physical components are known as “Hardware” Introduction to computer

4. Computer Categories 4 Desktop Computer Labtop PDA – Personal Digital Assistant Personal Computer High Computation Power Supercomputer  Mainframe Introduction to computer

5. Computer Systems  Hardware  Actual physical machines (equipment) that make up the computer 5  Software  Programs written for a specific application are often called softwares Introduction to computer

6. Computer Components CPU (Central Processing Unit) Primary storage (memory) Secondary storage (disks, tapes, etc.) Input devices (mouse, keyboard, etc.) Output devices (screen, printer, etc.) 6 Introduction to computer

7. Hardware - Process INPUT Processing Primary storage OUTPUT command Information result Secondary storage Introduction to computer

8. Computer Storage Primary Storage RAMROM Secondary Storage 8 Much Faster More expensive Slower Less expensive Can Read/Write Volatile Read Only Non - Volatile Introduction to computer

9. Data Representation 9  Data in computer is represented in “ bit ”  bit = binary digit 0 or 1  Byte = 8 bits  1 byte can represent many kinds of data 1 byte = 01100001 the above 1 byte means, “a” or 97 the meaning of 1 byte depends on the program 1 Kbyte = 2 10 = 1024 bytes 1 Mbyte = 2 20 = 1,048,576 bytes 1 Gbyte = 2 30 = 1,073,741,824 bytes 1 Tbyte = 2 40 = 1,099,511,627,776 bytes Introduction to computer

10. Outline 10  Introduction to computer  Programming Languages  C# Language Overview

11. Programming Languages 11  Program  A set of instructions for a computer to follow, written in specific programming language  Types of programming language  High-Level Language  Assembly Language  Machine Language Programming Languages

12. High-level VS Assembly VS Machine Language 12  High-level Language  Nearly like human word SUM := A * 2 + ALPHA/3;  Assembly Language  Some key words are understandable MULL3A, #2, R ADDL3R6, R7, SUM  Machine Language  Only “ 0 ” and “ 1 ” 00011000011 00011001111 10011000111 Computer itself understands only Machine language

13. Language translator 13 Interpreter / Compiler Hello World! _ High-level language static void Main( ) { Console.WriteLine("Hello World!"); } Assembly language pushl %ebp movl %esp, %ebp subl $8, %esp andl $-16, %esp Machine language 00011000110001110 00110001110101111 00011000110001110 Assembler Machine Programming Languages

14. High-Level Languages  Procedural Language  Fortran  Cobol  Basic  C  Pascal  Object-Oriented Language  C++  Java  C#  Functional Language  Lisp  Logic Language  Prolog 14 Programming Languages

15. Outline 15  Introduction to computer  Programming Languages  C# Language Overview

16. A simple C# Program 16 Grouping using { } C# Language Overview

17. A simple C# Program 17 Statement ending with semicolon “;” C# Language Overview

18. A simple C# Program 18 C# syntax is case-sensitive namespaceNAMEspace Main()main() C# Language Overview

19. A simple C# Program 19 White space means nothing static void Main(string[] args) { Console.WriteLine("Hello World!"); } static void Main(string[] args){ Console.WriteLine("Hello World!");} C# Language Overview

20. A simple C# Program 20 Anything between /* */ or after // is considered a comment static void Main(string[] args) //comment here { /* This is comment too. */ Console.WriteLine("Hello World!"); } Comments will not be translated C# Language Overview

21. Program Structure  The starting point of the program is:  This is known as the method Main  A method is put inside a class  A class may be put inside a namespace static void Main () {... starting point... } static void Main () {... starting point... } 21 C# Language Overview

22. Program Structure  In C#  A program can contain several namespaces  A namespace can contain several classes  A class can contain several methods  In other words  Think of a namespace as a container of classes  Think of a class as a container of methods method1 method2 namespace Class Class 22 C# Language Overview

23. Program Structure  For this 204111 course  Program with only one class and at most one namespace  For now until sometime before midterm  Program with one method (i.e., Main) namespace HelloW { class HelloWClass { static void Main () { System.Console.WriteLine("Hello World!"); System.Console.ReadLine(); } namespace HelloW { class HelloWClass { static void Main () { System.Console.WriteLine("Hello World!"); System.Console.ReadLine(); } 23 C# Language Overview

24. Naming Rules  Letters, digits and underscores(_)  First character  letter or _  Up to 63 characters long  Must not be a reserved word * Case Sensitive Example KU67 ≠ kU67 ≠ku67 KU67 ≠ kU67 ≠ ku67 C# Language Overview 24

25. Naming Rules  Letters, digits and underscores(_)  First character  letter or _  Up to 63 characters long  Must not be a reserved word C# Language Overview 25 Example nameName _data 9point  class  class_A class_”A”  point9

26. C# Reserved Words C# Language Overview 26

27. Any question?