1. Repetition – For and Do While
Yonglei Tao

2. Future Balance
You put $10,000 into a bank account that earns % interest per year.
How much will your account balance be in five years?

3. Calculation
After Year Calculation Balance 0 $10, balance = balance + balance * 0.05 $10, balance = balance + balance * 0.05 $11, balance = balance + balance * 0.05 $11, balance = balance + balance * 0.05 $12, balance = balance + balance * 0.05 $12,762.82

4. The For Loop
Dim balance, interest As Double balance = For year As Integer = 1 To 5 interest = balance * 0.05 balance = balance + interest Next year lblDisplay.Text = Format (balance, “currency”)

5. The Do While Loop
Dim balance, interest As Double Dim year As Integer ‘ declare control variable balance = year = 1 ‘ initialize control varaible Do While year <= 5 ‘ test control variable interest = balance * 0.05 balance = balance + interest year = year + 1 ‘ update control variable Loop lblDisplay.Text = Format (balance, “currency”)

6. A Problem
You put $10,000 into a bank account that earns 5% interest per year.
How many years does it take for the account balance to be double the original?

7. Calculation ….. After Year Calculation Balance 0 $10,000.00
$10,000.00
balance = balance + balance * $10,500.00
balance = balance + balance * $11,025.00
balance = balance + balance * $11,576.25
balance = balance + balance * $12,155.06
balance = balance + balance * $12,762.82
…..

8. The Do While Loop
Dim balance, interest As Double Dim year As Integer = 1 balance = Do While year <= 5 interest = balance * 0.05 balance = balance + interest year = year + 1 Loop lblDisplay.Text = Format (balance, “currency”)
balance < 20000

9. Find the Number of Iterations
i = 0.5 Do While i <= 1.3 lblDisplay.Text = lblDisplay.Text & i & “ “ i = i Loop Dim sum As Integer = 0 For i As Integer = 2 To 20 Step 5 sum = sum + i Next i