1. Loop Continue

2. Exiting a Loop Prematurely
In some cases it is necessary to end a loop before the test condition would end it
The following statements accomplish this
Exit Do (used in Do While or Until loops)
Exit For (used in For Next loops)

3. Years to Reach Targeted Future Value Future Value=Present Value
Years to Reach Targeted Future Value Future Value=Present Value*(1+Rate)Year

4. Method 1
Dim PresentValue, Rate, Target, YearToTarget, futureValue As Double
PresentValue = TextBox1.Text
Rate = TextBox2.Text
Target = TextBox3.Text
futureValue = PresentValue
YearToTarget = 1
Do While futureValue < Target
YearToTarget = YearToTarget + 1
futureValue = PresentValue * (1 + Rate) ^ YearToTarget
Loop
TextBox4.Text = YearToTarget.ToString

5. Method 2
Dim PresentValue, Rate, Target, YearToTarget, futureValue As Double
PresentValue = TextBox1.Text
Rate = TextBox2.Text
Target = TextBox3.Text
YearToTarget = 1
Do While true
futureValue = PresentValue * (1 + Rate) ^ YearToTarget
If futureValue >= Target Then
Exit Do
End If
YearToTarget = YearToTarget + 1
Loop
MessageBox.Show(YearToTarget.ToString)

6. Method 3
Dim PresentValue, Rate, Target, YearToTarget, futureValue As Double
PresentValue = TextBox1.Text
Rate = TextBox2.Text
Target = TextBox3.Text
For YearToTarget = 1 To 9999
futureValue = PresentValue * (1 + Rate) ^ YearToTarget
If futureValue >= Target Then
Exit For
End If
Next
MessageBox.Show(YearToTarget.ToString)

7. Searching: If fruit not exists, then add to the combobox

8. Code Example: Using Flag
Dim testItem As String
Dim myIndex As Integer
Dim foundFlag As Boolean = False
testItem = ComboBox1.Text
For myIndex = 0 To ComboBox1.Items.Count - 1
If ComboBox1.Items(myIndex) = testItem Then
foundFlag = True
Exit For
End If
Next
If foundFlag = True Then
MessageBox.Show("Items already exists")
Else
MessageBox.Show("Item not exists")
ComboBox1.Items.Add(testItem)

9. Method 2: Using VB’s tools
Dim testItem As String
testItem = ComboBox1.Text
If ComboBox1.Items.Contains(testItem) Then
MessageBox.Show("Items already exists")
Else
MessageBox.Show("Item not exists")
ComboBox1.Items.Add(testItem)
End If

10. A Loop that is Inside Another Loop is Called a Nested Loop

11. Nested Loop Example A clock is an example of a nested loop
Minute hand repeats 60 times for each hour
Second hand repeats 60 times for each minute
Dim hours, minutes, seconds As Integer
For hours = 0 To 24
For minutes = 0 To 59
For seconds = 0 To 59
MessageBox.Show("Hour: " + hours.ToString + " Minutes: " +
minutes.ToString + " Seconds: " + seconds.ToString)
Next seconds
Next minutes
Next hours

12. Nested Loop Dim i, j As Integer Dim outputLine As String
For i = 1 To 4
outputLine = ""
For j = 1 To 4
outputLine = outputLine + "(" + i.ToString + "," + j.ToString + ")"
Next
ListBox1.Items.Add(outputLine)
( 1, 1) ( 1, 2) ( 1, 3) ( 1, 4)
( 2, 1) ( 2, 2) ( 2, 3) ( 2, 4)
( 3, 1) ( 3, 2) ( 3, 3) ( 3, 4)

13. Nested Loop Multiplication Table

14. Code Example Dim i, j, product As Integer Dim outputLine As String
ListBox1.Items.Add(" ")
For i = 1 To 9
outputLine = i.ToString
For j = 1 To 9
product = i * j
outputLine = outputLine + " " + product.ToString("D2")
Next
ListBox1.Items.Add(outputLine)
Note: String(“D2”) with leading zero

15. Future Value=Present Value*(1+Rate)Year
Given PV, compute the FV starting from year 5 until specified year with a step of 5 and rate from 3% to specified rate with a step of 0.5%
Rate/Year
3.00% $1, $1, $1, $1,806.11
3.50% $1, $1, $1, $1,989.79
4.00% $1, $1, $1, $2,191.12
4.50% $1, $1, $1, $2,411.71
5.00% $1, $1, $2, $2,653.30

16. Code Example Dim rate, year, presentValue, futureValue As Double
presentValue = TextBox1.Text
Dim lineOutput As String
ListBox1.Items.Add("Rate/Year ")
For rate = 0.03 To 0.05 Step 0.005
lineOutput = rate.ToString("p2")
For year = 5 To 20 Step 5
futureValue = presentValue * (1 + rate) ^ year
lineOutput = lineOutput + " " + futureValue.ToString("c")
Next
ListBox1.Items.Add(lineOutput)
rate.ToString("p2")

17. Exercise
Create a monthly payment table for loans with term specified by user and rate range from 5% to any specified rate with an increment of .25% and loan from 100,000 to any specified loan with an increment of
Monthly payment table
term 30
Loan
rate 100, , , ,000
5% $ $ $1, $1,342.05
5.25% $ $ $1, $1,380.51
5.50% $ $ $1, $1,419.47
5.75% $ $ $1, $1,458.93
6% $ $ $1, $1,498.88