1. Lesson 5 McManus COP1006 1

2.  Algorithm Instructions  Sequential Logic Structure  Solution Development McManusCOP10062

3.  Terminal ◦ Starts, Stops, Ends  Input/Output ◦ Input data, Output information  Assign ◦ Apply values to variables  Process ◦ Execute instructions McManusCOP10063 Terminal Input/ Output Assign Process

4.  The oldest logic structure  The most used logic structure  The easiest structure to understand  Is one statement after another statement, after another statement, after another statement, etc. McManusCOP10064

5.  Enter Name  Enter Address  Enter City  Enter State  Enter Zip  Enter Hours  Enter Wage  Pay = Hours * Wage  Print Name  Print Address  Print City  Print State  Print Zip  Print Pay McManusCOP10065

6. McManus COP1006 6

7.  Elliott invests $5,000 in a savings account that yields 5% (.05) annual interest.  Assuming that all interest is left on deposit along with the original deposited amount ◦ What will be the equation to calculate the amount that will be in the account at the end of 10 years? ◦ How much will the interest be at the end of the 10 years? McManusCOP10067

8.  First: Research banking algorithms ◦ We wind up with Two Equations:  First…the Tough one  Amount = Principal * ((1 + Interest Rate) ^ Time)  Principal – amount to be invested  Interest Rate – yearly percentage rate  Time – investment period in years  Amount – principal + interest earned  Next…the Easy one  Interest = Amount – Principal  Interest – the actual amount of Interest McManusCOP10068

9. McManusCOP10069 Calculate Savings Get input Calculate Print Amount Print Interest Calculate Interest Calculate Amount Print

10.  Get Principal Amount  Get Yearly Interest Rate  Get Time Intervals  Calculate Amount of Principal + Interest  Amount = Principal * ((1 + Rate) ^ Time)  Calculate Amount of Interest  Interest = Amount - Principal  Print Amount of Ending Principal + Interest  Print Amount of Interest McManusCOP100610

11. In Visual Basic Note: Up to this point it didn’t matter what language we use… McManus COP1006 11

12. Variable NameData TypeModuleDefined DomainScope PrincipalDecimalGetInput Calculate 0 < n < 1 millionGlobal InterestRateDoubleGetInput Calculate 0 < n < 1 to 14+ digits Global TimeShortGetInput Calculate 0 < n < 32,767Global AmountSingleCalculate PrintResult 0 < n < 1 millionGlobal InterestSingleCalculate PrintResult 0 < n < 1 millionGlobal McManusCOP100612

13. ' Input Values by User Dim Principal As Decimal Dim InterestRate As Double Dim Time As Short ' Output Values Dim Amount As Single Dim Interest As Single McManusCOP100613 Internal Documentation taking the form of Comments

14. Private Sub cmdGetInput_Click() Principal = CDec(InputBox("In Dollar amount " & _ “ (5000)", "Please Enter Principal Amount")) InterestRate = CDbl(InputBox(" Ex. 5% " & _ “ would be entered as.05", "Please " & _ “ Enter Annual Interest Rate")) Time = CShort(InputBox("An Integer " & _ “ with no decimals", "Please Enter Length " & _ “ of Time in Years")) End Sub McManusCOP100614

15. Private Sub cmdCalculate_Click() ' Calculates Principal + Interest over time Amount = Principal * ((1 + InterestRate) ^ Time) ' Calculates amount of total Interest at end of ' time period Interest = Amount - Principal End Sub McManusCOP100615

16. Private Sub cmdPrintResult_Click() lstOutput.Items.Add(" The Amount of Principal + " & _ “Interest Paid on") lstOutput.Items.Add(" the Principal Amount of " & _ VB6.Format(Principal, "Currency") & " for ") lstOutput.Items.Add(Time & " years is") lstOutput.Items.Add(" " & _ VB6.Format(Amount, "Currency")) lstOutput.Items.Add(" and the Amount of Interest is") lstOutput.Items.Add(" " & _ VB6.Format(Interest, "Currency")) End Sub McManusCOP100616

17. McManusCOP100617

18. McManusCOP100618 1 st step 2 nd step 3 rd step

19. McManusCOP100619

20. McManusCOP100620

21.  Internal Documentation ◦ Takes the form of comments within the program ◦ Helped by using Mnemonic terms  Creates self-documenting code  External Documentation ◦ Takes the form of  User Manuals  Help Screens  System Documentation McManusCOP100621

22.  Input Variables to be tested ◦ Principal  any numeric value greater than 0 ◦ InterestRate  any numeric value greater than 0 and less than 1 ◦ Time  any integer greater than 0  Note: We didn’t do any Error checking in this problem. McManusCOP100622

23.  Output Variables ◦ Would expect to see the Amount a positive number greater than the Principal amount ◦ Would expect to see the Interest greater than zero.  Why are these statements important? McManusCOP100623

24.  Analyze the problem ◦ Being able to restate the problem is one indicator that you understand the problem  Develop the structure chart  Develop the algorithms  Develop the data dictionary  Develop the code  Test the solution McManusCOP100624

25. McManusCOP100625