หลักการเขียนโปรแกรมคอมพิวเตอร์เบื้องต้น โดยใช้ภาษา C# และใช้โปรแกรม RAPTOR ในการออกแบบ Flowchart

1. 5
Selecting Programming
Company
LOGO

2. 



Boolean Expression
If
Nested If
Switch…case

3. Boolean Expression





Comparison)
equal)
Not equal)
Less)
Greater)
Less than or equal to)

Greater than or equal
to)

4. X = 10 Y = "com")
X == 10
X != 10
X < 10
X > 10
X <= 10
X >= 10
y+"puter" == "computer"
Y == "Com"
Y != "com"
True
False
False
False
True
True
True
False
False

5. Boolean Expression

Boolean)
And)

Or)

Not)

6. A = 10,
B = 5, Y = "com", Z = true)
A == 10 && B+5 == A)
A + B > 10) && B == 5)
(B <= A) || (B == A)
!(10 == B)
!(A >= B)
(A == 10) && (Y == "com")
(Y == "Com") || (Y == "com")
(Y == "Com") || !(Z)
!(!(Z)) || !(Z)
True
False
True
True
False
True
True
False
True
True

7. If
If


condition)
If
if
if…else
True
else)
2
False

8. If
if (condition) statement;
(A=5, B=10)
If (A == B/2) Console.WriteLine("True");
if (condition)
statement;
If (B/2 == A)
Console.WriteLine(B+"/2 = " + A);
if (condition)
{
statement1;
statement2;
statement3;
:
}
If (A != B)
{
Console.WriteLine("A = {0}",A);
Console.WriteLine("B = {0}",B);
Console.WriteLine("{0} != {1}",A,B);
}

9. static void Main(string[] args)
{
int A = 5;
int B = 10;
if (A != B)
{
Console.WriteLine("A = {0}", A);
Console.WriteLine("B = {0}", B);
Console.WriteLine("{0} != {1}", A, B);
}
Console.ReadKey();
}

10. static void Main(string[] args)
{
char Member;
float Discount = 0f;
Console.Write("Are you Member (Y or N) : ");
Member = char.Parse(Console.ReadLine());
if ((Member == 'y') || (Member == 'Y'))
{
Discount = 0.05f;
}
Console.WriteLine("Discount is {0:p}",
Discount);
Console.ReadLine();
}

11. If…else
if (condition)
statement;
else
statement;
if (condition)
{
statement1;
statement2;
:
}
else
{
statement1;
statement2;
:
}
(A=5, B=10)
If (A == B)
Console.WriteLine(A+" = " + B);
else
Console.WriteLine(A+" != " + B);
If (A <= B)
{
Console.WriteLine("A = {0}",A);
Console.WriteLine("B = {0}",B);
Console.WriteLine("{0} <= {1}",A,B);
}
else
{
Console.WriteLine("A = {0}",A);
Console.WriteLine("B = {0}",B);
Console.WriteLine("{0} > {1}",A,B);
}

12. static void Main(string[] args)
{
int Age, Ticket;
Console.Write("How old are You? : ");
Age = int.Parse(Console.ReadLine());
if (Age >= 13)
{
Ticket = 50;
}
else
{
Ticket = 20;
}
Console.WriteLine("You are {0} years old",
Age);
Console.Write("The price of Ticket is "}
Console.Write("{0} Baht", Ticket);
Console.ReadLine();
}

13. Nested If
If
If
Nested If
If

14. Nested If
if (condition)
{
if (condition)
{
statement;
}
}
(A=13, B=60)
if (A == 13)
{
if (B == 60)
{
Console.WriteLine("A = {0} and B = {1}", A, B);
}
}

15. Nested If
if (condition)
{
if (condition)
{
statement;
}
}
else
{
if (condition)
{
statement;
}
}
(A=13, B=60)
if (salary < 1650)
{
SocialSecurity = 0;
}
else
{
if (salary < 15000)
{
SocialSecurity = salary * 0.05f;
}
else
{
SocialSecurity = 15000*0.05f;
}
}

17. 5
A-F

18. 50
If (Mark < 50)
F
60
If (Mark < 60)
D
70
If (Mark < 70)
C
80
If (Mark < 80)
B
A

19. 80
If (Mark >= 80)
A
70
If (Mark >= 70)
B
60
If (Mark >= 60)
C
50
If (Mark >= 50)
D
F

21. Switch…case
C#
Nested if
switch...case

22. switch (expression)
{
case constant-expression-1:
statements;
break;
case constant-expression-2:
statements;
break;
case constant-expression-3:
statements;
break;
:
default:
statements;
break;
}
Switch…case
using System;
namespace SwitchCase
{
class Program
{
static void Main(string[] args)
{
char Operator;
int A = 5, B = 10, Total;
Operator = char.Parse(Console.ReadLine());
switch(Operator)
{
case '+': Total = A + B; break;
case '-': Total = A - B; break;
case '*': Total = A * B; break;
case '/': Total = A / B; break;
default: Total = 0; break;
}
Console.WriteLine("Answer is {0}", Total);
}
}
}

23. Switch…case
RAPTOR
default
If
If
switch…case
switch…case
char)
switch…case
If
integer)
string)

24. Try…catch

C#
Console.ReadLine()
int
int
int.Parse(Console.ReadLine())
A
try…catch…finally
A

25. int Operator = 0;
int A = 5, B = 10, Total;
try
{
Operator = int.Parse(Console.ReadLine());
}
catch (Exception)
{
Console.WriteLine("Input is not integer...Error!!!");
}
finally
{
Console.WriteLine("Write everytime");
}

26. try...catch...finally






Run Time Process)
Init Process)
Block
try
Block
catch
Block
finally
1 try
Block catch
Block
finally
try
1 Block

27. 

5
/