Introduction to Computer and Programing Thanachat Thanomkulabut

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

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

Computer Categories 4 Desktop Computer Laptop, Notebook, Netbook PDA – Personal Digital Assistant Personal Computer High Computation Power Supercomputer and Mainframe Introduction to computer

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

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

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

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

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 = the above 1 byte represents character “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

ASCII Table 10

Outline 11  Introduction to computer  Programming Languages  C# Language Overview

Programming Languages 12  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

High-level VS Assembly VS Machine Language 13  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 ” Computer itself understands only Machine language

Language translator 14 Hello World! _ High-level language static void Main( ) { Console.WriteLine("Hello World!"); } Interpreter / Compiler Assembly language pushl %ebp movl %esp, %ebp subl $8, %esp andl $-16, %esp Machine language Assembler Machine Programming Languages

High-Level Languages  Procedural Language  Fortran  Cobol  Basic  C  Pascal  Object-Oriented Language  C++  Java  C#  Functional Language  Lisp  Logic Language  Prolog 15 Programming Languages

Outline 16  Introduction to computer  Programming Languages  C# Language Overview

A simple C# Program 17 Grouping using { } C# Language Overview

A simple C# Program 18 A statement must be ended with semicolon “;” C# Language Overview

A simple C# Program 19 C# syntax is case-sensitive namespaceNAMEspace Main()main() C# Language Overview

A simple C# Program 20 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

A simple C# Program 21 Anything between /* */ or after // is considered a comment Comments will not be translated C# Language Overview

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... } 22 C# Language Overview

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 23 C# Language Overview

Program Structure  For this 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(); } 24 C# Language Overview

Naming  C# allows user to give a name to something.  A user-defined name can be any word with some rules.  Remember!!! C# is a case-sensitive language. * Case Sensitive Example KU ≠ kU ≠ku KU ≠ kU ≠ ku C# Language Overview 25

Naming Rules  Letters, digits and underscores(_)  First character must be a letter or _  Up to 63 characters long  Must not be a reserved word C# Language Overview 26 Example nameName _data 9point class class_Aclass_"A" point9

C# Reserved Words C# Language Overview 27

More Resources  How Bits and Bytes Work (  Byte (  Computer hardware (  Software (  Programming language (  List of programming languages ( nguages) nguages 28

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