1. Project on VB Control Structures
Prepared By : Sudhir Kataria
PGT Computer Sc.
K V Chamera II

2. Detailed Lesson Plan

3. Project Summary
This project named “Control Structure” is mainly focused on the working principle of various control Structures in VB and their implementation in Programming.
Various Practical Examples have been included in this project relating to real life problems for the better understanding of the concepts.
Programming questions, Output related questions are formed so as to improve the logical & problem solving ability of the students.

4. Learning Objectives
Working principles of various types of control structures in VB.
Syntax & semantics of various statements in VB.
Implementation of Control structures in Programming.
Connecting real-world entities using control structures.
Solving real-life problems using control structures.
Enhancement of Logical & Problem solving ability of the learner.

5. Assessment Procedures
Students performance will be judged/assessed by inspecting the following factors :
Logic in Programming.
Efficiency & Effectiveness of Programs.
Usage of various control structures.
Correct syntax.
Correct code.
Following stylistic guidelines while programming i.e. object naming conventions, meaningful object names, proper indentation & spacing, prettyprinting style etc.

6. Implementation Procedures
Students will be explained about the working principle of individual statement with the help of its proper syntax and example.
After explaining working principle of every statement, students will be given Practical Examples, implemented using VB language on Computer.
Students will be demonstrated the usage and working of every statement in variety of ways, according to the options available in the syntax.

7. Implementation Procedures
Students will be given practical questions to solve and implement using VB language.
After implementing every type of control structure, students will be given a Home Assignment based on the statements studied.
Students will be given a consolidated Assignment in the end of the chapter so as to test the logical ability of the children and their understanding about the different types of control structures and their implementation.

8. Resources Used
I am in teaching profession from last 12 years so this complete lesson plan, assessment procedure, programming questions, output related questions etc., are formed with my previous experience and knowledge. Still I would like to mention few resources I have used for the preparation of this Project :
Text book of Informatics Practices by Sumita Arora.
Previous year CBSE Board question papers.
Computer.

9. Created By : Sudhir Kataria PGT Computer Sc. K V Chamera II
VB Control Structures
Created By : Sudhir Kataria
PGT Computer Sc.
K V Chamera II

10. Control Flow
In a program, statements may be executed sequentially, selectively or iteratively. Every programming language provides constructs to support sequence, selection or iteration. So there are three types of programming constructs :
Sequential Constructs
Selection Constructs
Iterative Constructs

11. Sequential Construct
The sequential construct means the statements are being executed sequentially. This represents the default flow of statements.
Stament 1
Stament 2
Stament 3

12. Selection Construct
The selection construct means the execution of statement(s) depending upon the condition-test. If a condition evaluates to true, a course-of-action (a set of statements) is followed otherwise another course-of-action is followed. This construct is also called decision construct as it helps in decision making.

13. Selection Construct One course-of-action true Statement 1 Statement 2
Condition ?
Statement 1
Statement 2
false
Statement 1
Another course-of-action
Statement 2

14. Iterative Constructs
The iterative or repetitive constructs means repetition of a set-of-statements depending upon a condition-test. A set-of-statements are repeated again and again till the condition or Boolean Expression evaluates to true. The iteration constructs are also called as looping constructs.

15. Iterative Construct false The exit condition True Statement 1?
The exit condition
True
Statement 1
The loop body
Statement 2

16. Selection Constructs VB provides two types of selection construct :
1) If statement
2) Select Case statement
The If Statement : If statement of VB comes in various forms & are given below:
1) If..Then Statement
2) If..Then..Else Statement
3) If..Then..ElseIf Statement
4) Nested Ifs

17. If..Then Statement
Def. : An If..Then statement tests a particular condition; if the condition evaluates to true, a course-of-action is followed otherwise it is ignored.
Syntax :
If (boolean expression) Then
statements
End If

18. If..Then Statement Example 1. : If (Num>0) Then
Print “It is a positive number”
End if
Example 2 :
If txtAge.Text>=18 Then
Print “You are eligible to vote”

19. If..Then..Else Statement
If..Then..Else statement provides an alternate choice to the user i.e. if the condition is true then a set of statements are executed otherwise another set of statements are executed.
Syntax :
If (boolean Expression) Then
VB Statement(s)
Else
End If

20. Examples of If..Then..Else
If txtAge.Text>=18 Then
Print “You are eligible to vote”
Else
Print “Sorry, You are not eligible to vote”
End If
Example 2 :
If Num Mod 2=0 Then
Print “It is an Even Number”
Print “It is an Odd Number”

21. If..Then..ElseIf Statement
If..Then..ElseIf statement is used to test a number of mutually exclusive cases and only executes one set of statements for the case that is true first.
Syntax :
If (Boolean Expression) Then
Statement(s)
ElseIf (Boolean Expression 2) Then
ElseIf (Boolean Expression 3) Then :
[ Else
End If

22. Example of If..Then..ElseIf
If (Age<=4) Then
Print “Your rate is free.”
ElseIf (Age<=12) Then
Print “You qualify for the children’s rate.”
ElseIf (Age<65) Then
Print “You must pay full rate”
Else
Print “You qualify for the seniors’ rate.”
End If

23. Nested Ifs
A nested If is an if that has another If in its if’s body or in its else’s body. The nested if can have one of the following three forms :
1. If (expresssion 1) Then
If (expression 2 ) Then
Statement 1
[Else
Statement 2
End If
Else
body-of-else]

24. Nested Ifs 2. If (expression 1) Then body-of-if Else :
Statement-1
[Else
Statement-2]
End If

25. Nested If’s 3) If (expression 1) Then : If (expression 2) Then
Statement-1
[Else
Statement-2]
End If
Else
If (expression 3) Then
Statement-3
Statement-4]

26. Example of Nested If’s If Num>0 Then
Print “It is a positive number”
Else
If Num<0 Then
Print “It is a negative number”
Print “The number is equal to zero”
End If

27. Select-Case Statement
Select-Case is a multiple branching statement and is used to executed a set of statements depending upon the value of the expression. It is better to use Select-Case statement in comparison to If..Then..ElseIf Statement when the number of checks are more. There are 3 different forms of using Select-Case statements and are given below :

28. Different forms of Select-Case
1. Select Case : Simplest Form [Exact match]
Select Case Expression
Case Value
’one or more visual basic statements
Case Else :
End Select

29. Example of Form 1 Select Case byMonth Case 1,3,5,7,8,10,12
number_of_days=31
Case 2
number_of_days=28
Case 4,6,9,11
number_of_days=30
End Select

30. Syntax of Form 2 Select Case : Second Form [Relational Test]
Select Case Expression
Case is relation :
’one or more visual basic statements
[Case Else :
End Select

31. Example of Form 2 Select Case marks Case Is < 50 Result = “Fail”
Result = “Grade B”
Case Is < 75
Result = “Grade A”
Case Else
Result = “Grade A+”
End Select

32. Third Form of Select Case
Select Case : Third Format [Range Check]
Select Case Expression
Case exp1 To exp2:
’one or more visual basic statements
[Case Else:
End Select

33. Example of Form 3 Select Case Age Case 2 to 4 : Print “PreNursery”
Case 4 to 6 : Print “Kindergarden”
Case 6 to 10 : Print “Primary”
Case Else : Print “Others”
End Select

34. Home Assignment 1
Write a program in VB to compare three no’s and print the smallest number among these no’s.
Write a program in VB to check the eligibilty of a person to vote. Display a message “You are eligible to vote” if the age of the person is greater than or equal to 18 otherwise print “Sorry! You are not eligible to vote”
Write a program to compare two no’s and then print the square and cube of the larger number among these no’s.

35. Home Assignment
Write a program to display the grade obtained by the child according to the marks obtained by him/her. Criteria for assigning the grades is given below : If marks are
>=90 - Grade is A
<90 and >80 – Grade is B
<80 and >=70 – Grade is C
<70 and >=60 – Grade is D
<60 – Grade is E

36. Iterative Constructs (Looping Structures)
Loop : A loop is said to be the set of instructions which are repeated again and again in a program.
Types of Loops in VB :
Sentinel-controlled Loop Structures : repeat statements until a special value called sentinel value (or the terminating value) is reached.
Counter-controlled Loop Structures : repeat the set of statements until the value specified by the counter variable is reached.

37. Looping Structures
VB offers broadly following three types of looping structures :
For..Next
Do Loop
a) Do While..Loop
b) Do..Loop While
c) Do Until..Loop
d) Do..Loop Until
While..Wend

38. For..Next Statement
This type of statement is used when the user knows in advance how many times the loop is going to be executed.
Syntax :
For <counter Variable>=<start_val> To <end_val> Step <increment/Decrement Value>
‘ One or more VB Statements
Next <counter Variable>

39. Examples Example 1 : Generate natural no’s from 1 to 100
For I = 1 To 100
Print I
Next I
Example 2 : Generate first 20 even no’s.
For E = 2 to 40 Step 2
Print E
Next E

40. More Examples
Example 3 : Generate odd no’s from 100 to 30 in a list box.
For O = 99 to 31 Step -2
ListO.AddItem(O)
Next O
Example 4 : Generate table of any number N.
For T = 1 To N
Print N; “*”; T; “=”; N*T
Next T

41. More Examples Example 5 : Find factorial of a given number N. : Fact=1
For I= 1 to N
Fact = Fact * I
Next I
Print “Factorial of ”; N; “=”; Fact

42. Home Assignment 2 Write Programs for the following problems :
To Generate all the natural no’s from 200 to 500.
To Generate the table of 10.
To Generate all the even no’s from 200 to 400 in reverse order.
To Print first 20 multiples of the number input by the user.

43. Do..Loop Structures
Do While..Loop : Do While loop is an entry controlled loop in which the condition is placed at the entry point. This statement executes the statements specified in the body of the loop till the condition evaluates to true. The loop may not be executed at all the if the condition is initially false.
Syntax :
Do While <condition or boolean expression>
‘ One or more VB Statements
Loop

44. Examples of Do While..Loop
Example 1 : Never executes loop
Dim A as Byte
A=10
Do While A>10
A=A-1
Loop
Example 2 : Executes loop
Dim P as Byte
P=20
Do While P>5
P=P-2

45. Do..Loop While
Do Loop While is an exit controlled loop as the condition is placed at exit point. The body of the loop is going to be executed at least once whether the condition evaluates to true or false. Loop is executed as long as the result of the condition remains true.
Syntax : Do
One or more VB Statements
Loop While <condition or Boolean Expression>

46. Examples Example 1 : Do num = InputBox (“Enter a number”)
sum = sum + num
Loop While num < > 0
Here the statements inside the loop will be executed once no matter what the comparison test evaluates to.

47. Do..Until Loop
Do Until loop is an entry controlled loop in which the condition is placed at the entry point. This statement executes the statements specified in the body of the loop till the condition evaluates to false. The loop may not be executed at all the if the condition is initially true.
Syntax :
Do Until <condition or boolean expression>
‘ One or more VB Statements
Loop

48. Examples of Do Until..Loop
Example 1 : Never executes loop
Dim A as Byte
A=10
Do Until A<10
A=A-1
Loop
Example 2 : Executes loop
Dim P as Byte
P=20
Do Until P<5
P=P-2

49. Do..Loop Until
Do Loop Until is an exit controlled loop as the condition is placed at exit point. The body of the loop is going to be executed at least once whether the condition evaluates to true or false. Loop is executed as long as the result of the condition remains false.
Syntax : Do
One or more VB Statements
Loop Until <condition or Boolean Expression>

50. Examples Example 1 : Do num = InputBox (“Enter a number”)
sum = sum + num
Loop Until num = 0
Here the statements inside the loop will be executed once no matter what the comparison test evaluates to.

51. While..Wend
While..Wend loop is functionally equivalent to the Do While..Loop. It executes a set of VB statements till the condition evaluates to true.
Syntax :
While <Condition>
one or more vb statements
Wend

52. Examples Example 1 : Generate the sum of first 10 natural no’s I = 1
While I<=10
Sum = Sum + I
I = I + 1
Wend
Print “Sum of 10 natural no’s = ” ; Sum

53. Nested Loops A loop within another loop is called as Nested Loop.
Example :
For I = 1 to 5
For J = 1 To 3
Print J
Next J
Print
Next I
Inner Loop
Outer Loop

54. Working of Nested Loops
In nested loops the inner loop is executed completely for one time execution of the outer loop. In the Previous example the Inner Loop will be executed three times for every execution of the outer loop.
Nested loops are very useful when there is a requirement to generate different kind of patterns as output.

55. Examples Sol : For I = 1 To 5 For J = 1 To I Print I; Next J Print
Example : Program to generate the output given below : 1
2 2
3 3 3
Sol :
For I = 1 To 5
For J = 1 To I
Print I;
Next J
Print
Next I

56. Home Assignment 3 – Nested Loops
Write programs to generate the following patterns :
1 2) A
A B
A B C
A B C D

57. Home Assignment 4 – Output Related Questions
Specify the output of the following output related questions, assume that variables are declared :
1) sum=0 2) sum = 0
For I = 1 To 4 p=2 : q=4
For J = 1 To 3 Do While p<=10
sum = sum + J If p Mod 2 = 0 Then
Next J sum = sum + p
Print “Sum = ”;sum End If
Next I p=p+1
Loop
Print sum

58. Output related questions
3) R=5 : S=3 4) M=2 : N=4
Do Do Until M>12
Print R, S N = N + M
R = R If M Mod 3 = 0 Then
If R = 7 Then N = N - M
Exit Do Else
End If N = N + M
S = S + R End If
Loop While R <=10 M=M+1
Loop
Print M, N

59. Home Assignment - 5
Programming Questions : Develop programs for the followings :
To generate the mirror image of the number entered by the user.
To generate the prime numbers between 100 and 700.
To Check whether the number entered by the user is a prime number or not.
To print first 30 multiples of the number entered by the user.
To generate the factorial of the number input by the user.

60. Home Assignment - 5
To generate the Fibonacci series upto first 15 terms i.e …………..
To find the sum of all the numbers divisible by 7 from 100 to 200.
To check whether the year entered by the user is leap year or not.
To find and print the sum of digits of the number entered by the user.
To find and print the product of digits of the number accepted from the user.

61. Assessment Tools
Students will be given Programming problems, output and error finding questions to test whether they understood the various concepts taught through this presentation.
Various parameters are used to check the understanding of the concept and its implementation in Programming.
All the parameters mention in the next slide have their own importance, so all these parameters needs to be checked by the Teacher teaching Programming.

62. Assessment Tool Parameter Specify whether Remark Logic
Correct/Incorrect
Effective
Yes/No
Efficient
Coding
Syntax
Following Naming Conventions