1. C# Programming

2. Outline 2
Programming Languages
C# Language Overview

3. Programming Languages3
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

4. High-level VS Assembly VS Machine Language
Programming Languages
High-level VS Assembly VS Machine Language 4
High-level Language
Nearly like human word
SUM := A * 2 + ALPHA/3;
Assembly Language
Some key words are understandable
MULL3 A, #2, R
ADDL3 R6, R7, SUM
Machine Language
Only “0” and “1”
Computer itself understands only Machine language

5. Language translator Hello World! _ Machine language
Programming Languages
Language translator 5
Interpreter
/ Compiler
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
Assembler
Machine
Hello World! _

6. High-Level Languages Procedural Language Functional Language
Programming Languages
High-Level Languages 6
Procedural Language
Fortran
Cobol
Basic C
Pascal
Object-Oriented Language
C++
Java C#
Functional Language
Lisp
Logic Language
Prolog

7. Outline 7
Programming Languages
C# Language Overview

8. C# Language Overview
A simple C# Program 8
Grouping using { }

9. A simple C# Program Statement ending with semicolon “;”
C# Language Overview
A simple C# Program 9
Statement ending with semicolon “;”

10. A simple C# Program C# syntax is case-sensitive namespace NAMEspace
C# Language Overview
A simple C# Program 10
C# syntax is case-sensitive
namespace
NAMEspace
Main()
main()

11. A simple C# Program White space means nothing
C# Language Overview
A simple C# Program 11
White space means nothing
static void Main(string[] args) {
Console.WriteLine("Hello World!"); }
static void Main(string[] args){
Console.WriteLine("Hello World!");}

12. C# Language Overview
A simple C# Program 12
Anything between /* */ or after // is considered a comment
Comments will not be translated
static void Main(string[] args) //comment here {
/* This is comment too. */
Console.WriteLine("Hello World!"); }

13. Program Structure The starting point of the program is:
C# Language Overview
Program Structure 13
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 }

14. Program Structure In C# In other words
C# Language Overview
Program Structure 14
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
namespace
Class
method1
method2
Class

15. Program Structure For this 1204452 course
C# Language Overview
Program Structure 15
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(); }

16. Naming Rules MSU53 ≠ msU53 ≠ msu53 Letters, digits and underscores(_)
C# Language Overview
Naming Rules 16
Letters, digits and underscores(_)
First character letter or _
Up to 63 characters long
Must not be a reserved word
* Case Sensitive Example
MSU53 ≠ msU53 ≠ msu53

17. Naming Rules         Letters, digits and underscores(_)
C# Language Overview
Naming Rules 17
Letters, digits and underscores(_)
First character letter or _
Up to 63 characters long
Must not be a reserved word
Example  
name 
Name
point9
9point  
_data
class 
class_A 
class_”A” 

18. C# Language Overview
C# Reserved Words 18

19. Any question?

20. C# Basic Concept

21. Outline C# Beginning Variable and Constant Expression Statement22
C# Beginning
Variable and Constant
Expression
Statement
Modify-And-Assign
Math Class

22. C# Beginning The starting point of the program is:23
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 }

23. Inside method Main Variable declarations Statements
C# Beginning
Inside method Main 24
Variable declarations
Statements
static void Main(string[] args) {
const double pi = ;
int radius;
double area;
radius = int.Parse(Console.ReadLine());
area = pi*radius*radius;
Console.WriteLine(area); }

24. Outline C# Beginning Variable and Constant Expression Statement25
C# Beginning
Variable and Constant
Expression
Statement
Modify-And-Assign
Math Class

25. A variable is used to store “data.”
Variable & Constant
What is Variable? 26
A variable is used to store “data.”
“It must be declared before used”

26. Data Types Type Size Description Range bool 1 byte Store truth value
Variable & Constant
Data Types 27
Type
Size
Description
Range
bool
1 byte
Store truth value
true / false
char
Store one character
character code 0 – 255
byte
Store positive integer
0 – 255
short
2 byte
Store integer
-32, ,767
int
4 byte
-2.1 x x 109
long
8 byte
-9.2 x x 1018
double
16 byte
Store real number
± 5.0x ± 1.7x10308
string
N/A
Store sequence of characters

27. C# Variable Declaration
Variable & Constant
C# Variable Declaration 28
Syntax:
<data type> <name>;
Example:
We can also assign its initial value. Example:
int radius;
double area;
bool isokay;
int k = 200;
bool done = false;

28. C# Variable Declaration29
Syntax:
<data type> <name_1>, <name_2>,..., <name_n>;
Example:
We can also assign its initial value. Example:
int width, length, height;
double mean, sd, max, min;
bool isokay, isright, check;
int width=5, length, height=4;

29. Test I - Variable Declaration30
Declare variable1
Name : num_Student
Type : interger
Initial value : nothing
Declare variable2
Name : gender
Type : character
Initial value : m
Declare variable3,4,5
Name3 : u
Name4 : t Name5 : a
Type : double
Initial value3 : 5.0
Initial value4 : nothing
Initial value5 : 9.8

30. C# Constant Declaration
Variable & Constant
C# Constant Declaration 31
Syntax:
const <data type> <name> = <value>;
Example:
const int radius = 15;
const double area=1.5;
const bool isokay=true;
const string movie=”StarWarIII”;
const char mckazine=‘m’;

31. C# Constant Declaration
Variable & Constant
C# Constant Declaration 32
Syntax:
const <data type> <name_1> = <value_1>, <name_2> = <value_2>, ... , <name_n> = <value_n>;
Example:
const int radius = 15, height = 5;
const double area=1.5, wide=3.2, lenght = 4.1;

32. Test II - Constant Declaration33
Declare Constant
Name : e
Type : double
Initial value :

33. Outline C# Beginning Variable and Constant Expression Statement34
C# Beginning
Variable and Constant
Expression
Statement
Modify-And-Assign
Math Class

34. C# Expression Expression Arithmetic Expression Boolean Expression35
Expression
Arithmetic Expression
Boolean Expression

35. Arithmetic Expression36
Operators
+ - * /
% (remainder after division)
Example 
39 / 5 
39.0/5 
39 % 5 
5.0 % 2.2  16 7
7.8 4
0.6

36. Piority of Arithmetic Operators
Expression
Piority of Arithmetic Operators 37
Priority
operator 1
Parentheses () 2
*, / , % 3
+, - 4
If equal precedence, left to right
Answer
int a, b;
a = 2-10*3/5+(6%4);
b = 5*(15%4+(2-3))/9;
a = -2
b = 1

37. Calculation Priority static void Main(){ int a,b,c,d; double e,f,g;
Expression
Calculation Priority 38
static void Main(){
int a,b,c,d;
double e,f,g;
a=2; b=7; c=5;
d=c/a;
e=5/b;
f=5.0/2;
g=5/2.0; }
Answer
d = 2
e = 0
f = 2.5
g = 2.5

38. Boolean Expression Operators Comparison Boolean Equal == Not equal !=39
Operators
Comparison
Equal ==
Not equal !=
Less <
Greater >
Less than or equal to <=
Greater than or equal to >=
Boolean
And &&
Or ||
Not !
0 and 0 = 0
0 and 1 = 0
1 and 0 = 0
1 and 1 = 1
0 or 0 = 0
0 or 1 = 1
1 or 0 = 1
1 or 1 = 1
not 0 = 1
not 1 = 0

39. Example: Boolean Expression40
10 > 50 
’A’ < ’B’ 
(3<2) || (2+5 > 6) 
(’a’ != ’z’) && !(9==0) 
false
true
true
true

40. Outline C# Beginning Variable and Constant Expression Statement41
C# Beginning
Variable and Constant
Expression
Statement
Modify-And-Assign
Math Class

41. Statements A statement is a unit of command to instruct your program42
A statement is a unit of command to instruct your program
A method consists of one or more statements
Statement#1
class Hello {
static void Main () {
Console.WriteLine("Hello World!");
Console.ReadLine(); }
Statement#2

42. C# Statement Types C# Statement Types Assignment Statement43
C# Statement Types
Assignment Statement
Input Statement
Output Statement

43. Assignment Statement Assigning value to variable44
Assigning value to variable
Use the equal sign (=) when making assignments.
Syntax:
<variable> = <expression>;
int Width,High;
Width=10;
High=20+Width;

44. Input Statement Console.ReadLine() Return string45
Console.ReadLine() Return string
Use to get the input from user
Convert string to other data type
int.Parse()
Convert string to integer
double.Parse()
Convert string to double
Example
string st;
st = Console.ReadLine();

45. Example: Input Statement46
Ex1:
string myname;
myname = Console.ReadLine();
Ex2:
int Width;
string temp1;
temp1 = Console.ReadLine();
Width = int.Parse(temp1);

46. Statement
Output Statements 47
Use the method Write or WriteLine in the Console class (which is in System namespace)
Basic usage:
Advanced usage:
Even more advanced usage:
Console.WriteLine("Hello");
Console.WriteLine(area);
Console.WriteLine(”Size {0}x{1}”, width, height);
double salary=12000;
Console.WriteLine("My salary is {0:f2}.", salary);

47. Outline C# Beginning Variable and Constant Expression Statement48
C# Beginning
Variable and Constant
Expression
Statement
Math Class

48. The Math Class Value returned Example Call Result PI Value of π49
Method/ Constant
Value returned
Example Call
Result PI
Value of π
Math.PI
Max(x,y)
Larger of the two
Math.Max(1,2) 2
Abs(x)
Absolute value of x
Math.Abs(-1.3)
1.3
Sqrt(x)
Square-root of x
Math.Sqrt(4.0)
2.0
Round(x)
Nearest integer to x
Math.Round(0.8) 1
Pow(x,y) xy
Math.Pow(3,2)
9.0
Log(x)
Natural log of x
Math.Log(10)
Ceiling(x)
Smallest integer greater than or equal to x
Math.Ceiling(4.1) 5
Cos(x)
Cosine of x radians
Math.Cos(Math.PI) -1

49. Test III Write the program which Input : Your name50
Write the program which
Input : Your name
Output : Your name is <your name>.

50. Test IV Write the program which Input : 3 number51
Write the program which
Input : 3 number
Output : average of 3 input number

51. Test VI Write the program which Input : lenght of radius of circle52
Write the program which
Input : lenght of radius of circle
Output : Area of circle

52. Any question?

53. Selection Statement

54. Outline Boolean expression if statement nested if statement Flowchart*
Boolean expression
if statement
nested if statement
Flowchart

55. Boolean Expression Boolean Operators Comparison Equal == Not equal !=*
Operators
Comparison
Equal ==
Not equal !=
Less <
Greater >
Less than or equal to <=
Greater than or equal to >=
Boolean
And &&
Or ||
Not !
! Exclamation mark
0 and 0 = 0
0 and 1 = 0
1 and 0 = 0
1 and 1 = 1
0 or 0 = 0
0 or 1 = 1
1 or 0 = 1
1 or 1 = 1
not 0 = 1
not 1 = 0

56. Boolean Expression Example*
From the equation: X2+9X+10 = 0
How can we check that value of X is the answer for above equation?
Condition: Is value Y even number?
((X*X +9*X +10) == 0) //true if X is the answer
(Y%2 == 0) //true if Y is even OR
(Y%2 != 1) //true if Y is even

57. Example: Boolean Expressions*
double x = 4.0;
Expression Value
x < ___________
x > ___________
x <= ___________
5.0 == x ___________
x != ___________
(3!=4)&&(7<5) ___________
(4>4)||(5<=10) ___________
true
false
true
false
true
false
true

58. Outline Boolean expression if statement nested if statement*
Boolean expression
if statement
nested if statement
switch case statement
Flowchart

59. ที่มาของภาพ http://www.ryt9.com/s/prg/774090
if statement *
ที่มาของภาพ 10

60. if statement
if statement *
Execute the specific statement when the ”condition” becomes true
Syntax:
true
true
if (condition) {
statement; }
if (condition) {
statement1;
statement2; }

61. if statement
if statement *
Execute the specific statement when the ”condition” becomes true
Syntax:
true
if (condition)
statement;
if (condition) {
statement1;
statement2; }
true
if (condition) {
statement; }

62. if statement condition if (condition) { statement; } False True*
condition
False
True
Statement
if (condition) {
statement; }

63. if statement if (condition) statement; condition if (condition) {*
if (condition)
statement;
condition
False
True
Statement
if (condition) {
statement; }

64. if statement if (condition) { statement1; statement2; condition } True*
if (condition) {
statement1;
statement2; }
condition
False
True
Statement1
Statement2

65. if statement price = 40; price = 40; false true*
price = 40;
height<=140
price = 40;
if (height <= 140) {
Console.WriteLine (“Hello Children!”);
price = 0; }
Console.WriteLine (“price ={0}”,price);
false
true
Console.WriteLine (“Hello children”);
price = 0;
Console.WriteLine (“price = {0}”, price) 12

66. การควบคุมการไหลของโปรแกรม
โปรแกรมทั่วไปจะทำงานเป็นเส้นตรง
x = int.Parse(Console.ReadLine());
y = int.Parse(Console.ReadLine());
Console.WriteLine(x+y)
Console.WriteLine("Hello {0}",x)
z = x * y + 10;
Console.WriteLine(z) 14

67. การควบคุมการไหลของโปรแกรม
โปรแกรมที่ใช้คำสั่ง if
height <= 140
True
False
price = 40;
if (height <= 140) {
Console.WriteLine("Hello kids!");
price = 0; }
Console.WriteLine("price={0}",price);
เมื่อ height = 160
เมื่อ height = 120 15

68. ที่มาของภาพ http://splinedoctors.com/2009/02/hurry-up-and- choose/
if – else statements
ที่มาของภาพ choose/ 25

69. คำสั่ง if-else
คำสั่ง if
คำสั่ง if-else 26

70. if…else… statement If condition is true → execute statement1
if statement
if…else… statement *
If condition is true → execute statement1
If condition is false → execute statement2
Syntax:
if (condition)
statement1; //true
else
statement2; //false
if (condition)
statement1; //true
else {
statement2; //false
statement3; //false }

71. if…else… statement if (condition) { statement1; //true } else {
if statement
if…else… statement *
condition
False
True
Statement2
Statement1
if (condition) {
statement1; //true
} else {
statement2; //false }

72. if…else… statement if (condition) { statement1; //true } else {
if statement
if…else… statement *
condition
False
True
Statement2
Statement1
Statement3
if (condition) {
statement1; //true
} else {
statement2; //false
statement3; //false }

73. if…else… statement example
if statement
if…else… statement example *
Write the program which check input number.
input : integer number
output : message to inform that number is odd or even.
Value in N
Output
Even Number
It’s even number.
Odd Number
It’s odd number.

74. if…else… statement example
if statement
if…else… statement example *
Value in N
Output
Even Number
It’s even number.
Odd Number
It’s odd number.
if(n%2 == 0) {
Console.WriteLine(“It’s even number”);
} else {
Console.WriteLine(“It’s odd number”); }

75. การควบคุมการไหลของโปรแกรม
Console.WriteLine ("It is an even number");
n % 2 == 0
True
False
Console.WriteLine ("It is an odd number"); 30

76. if statement
Test I *
Write the program which decide result of the examination from student’s score
input : number
output :
score
output
less than 50
fail
otherwise
pass

77. Test II Write the program which find the value of function
if statement
Test II *
Write the program which find the value of function
input : number
output :
f(x) x
x2+1
x<0
x+2
x≥0

78. Thinking corner x > 0 x == 0 x < 0*
Write the program which decide type of integer input - positive, zero or negative integer.
x > 0
x == 0
x < 0

79. Outline Boolean expression if statement nested if statement*
Boolean expression
if statement
nested if statement
switch case statement
FlowChart

80. มุมนักคิด x > 0 x < 0 x == 0 x > 0 x < 0 True False True34

81. Nested if statement int N; N = int.Parse(Console.ReadLine());*
int N;
N = int.Parse(Console.ReadLine());
if (N > 0) {
Console.WriteLine(“N is positive number”);
else
if (N==0)
Console.WriteLine(“N is zero number”);
Console.WriteLine(“N is negative number”);
if#1
if#2

82. Nested if statement int N; N = int.Parse(Console.ReadLine());*
int N;
N = int.Parse(Console.ReadLine());
if (N >= 0) {
if (N==0)
Console.WriteLine(“N is zero number”);
else
Console.WriteLine(“N is positive number”); }
Console.WriteLine(“N is negative number”);
if#1
if#2

83. Exercise 1: Separated IF (simple)*
1. Have you eaten lunch?
2. Do you like noodle?
if (eaten==true)
{Console.WriteLine(“ I’ve already eaten”);}
else
{Console.WriteLine(“ I’ve not eat yet”);}
if (like_noodle==true)
{Console.WriteLine(“I like noodle”);}
{Console.WriteLine(“I don’t like noodle”);}

84. Exercise 2: Related two IF (full version)*
1. Do you like noodle?
2. If you don’t like noodle, do you like fried rice?
if (like_noodle==true)
{Console.WriteLine(“I like noodle”);}
else
{ Console.WriteLine(“I don’t like noodle”);
if (like_friedrice==true)
{Console.WriteLine(“I like fried rice”);}
{Console.WriteLine(“I don’t like fried rice”);} }

85. Exercise 2: Related two IF (short version)*
1. Do you like noodle?
2. If you don’t like noodle, do you like fried rice?
if (like_noodle==true)
{Console.WriteLine(“I like noodle”);}
else if (like_friedrice==true)
{Console.WriteLine(“I like friedrice”);}
else
{Console.WriteLine(“I don’t like friedrice”);}

86. Exercise 3: Nested two IF (short version)*
1. Do you like noodle?
1.1 If you like noodle, do you love Sen-Yai?
1.2 If you don’t like noodle, do you like fried rice?
if (like_noodle==true)
{Console.WriteLine(“I like noodle”);
if (love_SenYai==true)
{Console.WriteLine(“I love Sen-Yai”);}
else
{Console.WriteLine(“I don’t love Sen-Yai”);} }
else if (like_friedrice==true)
{Console.WriteLine(“I like fried rice”);}
{Console.WriteLine(“I don’t like fried rice”);}

87. Nested if statement example*
Write the program which show student’s grade
input : score of student
output :
Score
Grade
80 – 100 A
70 – 79 B
60 – 69 C
50 – 59 D
0 – 49 F

88. Test III Selfish Ratio Recieving Selfish Ratio = Giving Ratio Output
if statement
Selfish Ratio
Selfish Ratio =
Recieving
Giving
Ratio
Output
More than 1
You are selfish 1
You break even
Less than 1
You are giver

89. Nested if statement
Test III *
Write the program which calculation value of following function
input : value of x
output : function value of x according with ...
f(x) =
2x+10, x ≤ 5
x2+10, < x ≤ 20
x3+10, x > 20

90. Outline Boolean expression if statement nested if statement Flowchart*
Boolean expression
if statement
nested if statement
Flowchart

91. Flowchart Symbols Overview*
Graphical representation
Terminator
Process
Input/output
ข้าวหลามตัด = diamond
Condition
Connector
Flow line

92. Program Flowchart Example*
Start
Statement1
Statement2
Statement3
Statement4
End

93. if statement flowchart
Start *
statement1;
if (condition)
statement2; //true
else {
statement3; //false }
statement4;
Statement1
Condition
true
false
Statement2
Statement3
Statement4
End

94. if statement flowchart
Start *
n=int.Parse(Console.ReadLine());
n= int.Parse(Console.ReadLine());
if (n>0)
n= 2*n+5;
else {
Console.Write(“Go”);
n = n%4; }
n>0
false
true
Console. Write(“Go”);
n=2*n+5;
n=n%4;
End

95. Any question?