Introduction to Computer and ProgramingThanachat Thanomkulabut
Outline2
Introduction to computer Programming Languages C# Language Overview
Definition of Computer3
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 Categories4
• 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
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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.)
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Introduction to computer
Hardware - Process
INPUT
Processing
Primary storage
OUTPUT
command
Information
result
Secondary
storage
Introduction to computer
Computer Storage
RAM ROM
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Introduction to computer
Primary Storage
Secondary StorageRead OnlyNon - Volatile
Can Read/Write
Volatile
Much FasterMore
expensive
SlowerLess
expensive
Computer Storage
Data Representation9
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 represents character “a” or
97 the meaning of 1 byte depends on the
program1 Kbyte = 210 = 1024 bytes1 Mbyte = 220 = 1,048,576 bytes1 Gbyte = 230 = 1,073,741,824 bytes1 Tbyte = 240 = 1,099,511,627,776 bytes
Introduction to computer
ASCII Table10
Outline11
Introduction to computer Programming Languages C# Language Overview
Programming Languages12
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
Programming Languages
High-level VS Assembly VS Machine Language
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High-level Language Nearly like human word
SUM := A * 2 + ALPHA/3;
Assembly Language Some key words are understandable
MULL3 A, #2, RADDL3 R6, R7, SUM
Machine Language Only “0” and “1”
0001100001100011001111 10011000111
Computer itself understands only Machine language
Language translator14
Hello World!
_
High-level language•static void Main( )
{ Console.WriteLine("Hello
World!");}
Interpreter/ Compiler
Assembly language•pushl %ebp
movl %esp, %ebpsubl $8, %espandl $-16, %esp
Machine language• 00011000110001110
0011000111010111100011000110001110
Assembler
Machine
Programming Languages
High-Level Languages
Procedural Language Fortran Cobol Basic C Pascal
Object-Oriented Language C++ Java C#C#
Functional Language Lisp
Logic Language Prolog
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Programming Languages
Outline16
Introduction to computer Programming Languages C# Language Overview
A simple C# Program17
Grouping using { }
C# Language Overview
A simple C# Program18
A statement must be ended with semicolon “;”
C# Language Overview
A simple C# Program19
C# syntax is case-sensitive
namespace NAMEspace
Main() main()
C# Language Overview
A simple C# Program20
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# Program21
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 ... }
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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
method1method1
method2method2
namespacenamespace
ClassClass
ClassClass
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C# Language Overview
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(); } }}
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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 ≠ kuku
C# Language Overview
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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
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Example
name Name
_data
9point
class class_A class_"A"
point9
C# Reserved WordsC# Language Overview
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More Resources
How Bits and Bytes Work (http://www.howstuffworks.com/bytes.htm)
Byte (http://en.wikipedia.org/wiki/Byte) Computer hardware
(http://en.wikipedia.org/wiki/Computer_hardware)
Software (http://en.wikipedia.org/wiki/Software) Programming language
(http://en.wikipedia.org/wiki/Programming_language)
List of programming languages (http://en.wikipedia.org/wiki/List_of_programming_languages)
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Any question?
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