Category Archives: 2. Software Development

A program is required which will take in a student’s Standard Grade ComputingStudies grade and decide which course, Intermediate 1, Intermediate 2 or Higheris the most appropriate. Standard Grade is issued on a scale of 1 to 7.

Write the pseudocode for the part of the program which checks that the grade entered is a number between 1 and 7. (You should not need all the lines given!)
Write the Visual BASIC line of code which displays a message box if an invalid grade is entered. The grade is stored in a variable called grade.
Write the Visual BASIC line of code which displays a message box showing “Int 2” when the grade entered is either a 3 or a 4. The grade is stored in a variable called grade.
Explain briefly what each of the following algorithms does:

Input validation
Finding a maximum
Finding a minimum
Counting occurrences
Linear search

4b. Write the pseudocode for the algorithms above
5. An array can be used to store variables. Explain what an array is, by using an example.

The values I am going to store in my example are:
I am going to create my array using this line of Visual BASIC code:
My array works like this:

2. Software Development, Computing Higher

Dice Roll Program

November 4, 2011 Mr Stratton

Public Class Form1

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click '1 Set up Var Dim dice(6000) As Integer Dim results(6) As Integer Dim target As Integer

'2 Roll 6000 dice Call RollDice(dice)


'3 For Each Side of the dice

For Target = 1 To 6

'4 Count each side

Call count_occurrences(Target, dice, results(Target))

'5 next

Next
'6 Display

Call Display(results)

End Sub
Private Sub RollDice(ByRef dice() As Integer)

Dim counter As Integer

Randomize()

For counter = 1 To 6000

dice(counter) = Int(Rnd() * 6) + 1

Next

End Sub
Private Sub count_occurrences(ByVal target As Integer, ByRef Int_array() As Integer, ByRef counter As Integer)

'counting occurrences with an array of 10 strings

Dim pointer As Integer

counter = 0

For pointer = 1 To 6000

If Int_array(pointer) = target Then counter = counter + 1

Next

End Sub

Private Sub Display(ByRef results() As Integer) Dim Counter 'clear listbox lstOutput.Items.Clear() 'Display For Counter = 1 To 6 lstOutput.Items.Add(Counter & vbTab & results(Counter)) Next End Sub End Class

2. Software Development, Computing Higher

Module Library

October 26, 2011 Mr Stratton

Function getValidNumber(byVal Min As Single, byVal Max As Single) As Single

‘ Call this function with parameters for Min and Max

‘ Example

‘ Number2 = getValidNumber(-10, 10)

Dim Num As Single

Dim NumberOK As Boolean

NumberOK = False

Do

Num = InputBox(“Enter a number between ” & Min & ” and ” & Max)

If (Num >= Min) And (Num <= Max) Then NumberOK = True

If Not NumberOK Then MsgBox (“That was not in the valid range”)

Loop Until NumberOK

Return Num

End Function

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Private Sub fill_int_array (ByRef local_array() As Integer)

‘ fill a 10 element 1-D array with integers

‘ Example

‘ Call Fill_int_Arry(newNumber())

Dim index As integer

For index = 0 to 9

local_array(index) = InputBox(“Enter integer for element ” & index)

Next

End Sub

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Private Sub fill_random_int_array (ByRef local_array() As Integer)

‘ fill a 10 element 1-D array with random integers

‘ Example

‘ CAll fill_random_int_arry(RndNumbers())

Dim index As integer, Num As Integer

Randomize

For index = 0 to 9

Num = Int (Rnd * 100) + 1

local_array(index) = Num

Next

End Sub

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Private Sub display_int_array (ByRef local_array() As Integer)

‘display a 1-D array in 2 list boxes

‘ Exaple

‘ Call Display_Int_Array(RndNumbers())

Dim index As integer

For index = 0 to 9

lstIndex.Items.Add (index)

lstElement.Items.Add (local_array(index))

Next

End Sub

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Private Sub linear_search1(ByVal target As Integer, ByRef int_array() As Integer, ByRef position As Integer)

‘basic linear search on array of integers

Dim pointer As Integer

Dim found As Boolean

found = False

For pointer = 0 To 9

If int_array(pointer) = target Then

MsgBox (“Target found at position ” & pointer)

found = True

position = pointer

End If

Next

If Not found Then MsgBox (“Target not found in array”)

End Sub

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Private Sub linear_search2(ByVal target As String, ByVal max_index As Integer, ByRef test_array() As String, ByRef position As Integer)

‘more efficient linear search on array of strings

Dim pointer As Integer

Dim found As Boolean

found = False

pointer = 0

Do While (found = False) And (pointer <= max_index)

If test_array(pointer) = target Then

MsgBox(“Target found at position ” & pointer)

found = True

position = pointer

End If

pointer = pointer + 1

Loop

If Not found Then MsgBox(“Target not found in array”)

End Sub

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Private Sub count_occurrences(ByVal target As String, ByRef char_array() As String, ByRef counter As Integer)

‘counting occurrences with an array of 10 strings

Dim pointer As Integer

counter = 0

For pointer = 0 To 9

If char_array(pointer) = target Then counter = counter + 1

Next

End Sub

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Private Sub find_minimum(ByRef num_array() As Single, ByRef minimum As Single)

‘finding minimum in an array of 10 real numbers

Dim pointer As Integer

minimum = num_array(0)

For pointer = 0 To 9

If num_array(pointer) < minimum Then minimum = num_array(pointer)

Next

End Sub

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Private Sub find_maximum(ByRef int_array() As Integer)

‘finding maximum in an array of integers

Dim pointer As Integer

Dim maximum As Integer

maximum = int_array(0)

For pointer = 0 To 14

If int_array(pointer) > maximum Then maximum = int_array(pointer)

Next

MsgBox (“The largest number in that list was ” & maximum)

End Sub

2. Software Development, Computing Higher

Logical & Syntax Errors

September 14, 2011 Mr Stratton

Here is the pseudo code and VBE code we used today.

If Percent<45 Then

Display Fail

Elseif Percent>=45 Then

Display D

Elseif Percent>=50 then

Display C

Elseif Percent>=60 then

Display B

Elseif Percent>=75then

Display A

Else

Display “Error”

End IF

VB Code

Dim Percent As Integer

Percent = InputBox(“Please enter the percentage”)

If Percent >= 75 Then

MsgBox(“A”)

ElseIf Percent >= 60 Then

MsgBox(“B”)

ElseIf Percent >= 50 Then

MsgBox(“C”)

ElseIf Percent >= 45 Then

MsgBox(“D”)

ElseIf Percent < 45 Then

MsgBox(“Fail”)

Else

MsgBox(“Error”)

End If

Remember the last Else is a error trap and if your program works correctly you should never see it.

2. Software Development

Times Table V2 – Solution

August 25, 2011 Mr Stratton

Set up variables
For 12 Tables
For 12 sums
Calculate the answer to the current sum
Display the sum
Next sum
Next Table
end program

Refine Step 4

4.1 multiply the user’s number by the current position in the times table and store in answer

Refine Step 5

5.1 Display the user’s number multiplied by position equals to the answer

This is an example of a nested loop, a nested loop is a loop within a loop.

2. Software Development

Times Table V1 Design

August 24, 2011 Mr Stratton

Set up variables
Ask for and get the times table from user
For 12 sums
Calculate the answer to the current sum
Display the sum
Next sum
end program

Refine Step 4

4.1 multiply the user’s number by the current position in the times table and store in answer

Refine Step 5

5.1 Display the user’s number multiplied by position equals to the answer

2. Software Development

Step wise refinement.

August 19, 2011 Mr Stratton

We created a very simple design for a program that allowed the user to add two numbers together. We discussed at length the need for clear and concise steps. These allow the programmer and other to plan the flow of the program.

Add 2 numbers Mr. Stratton

Get 2 numbers
Add the two numbers
Display the answer

Refine Step 1

1.1 Ask for first number

1.2 Store First Number

1.3 Ask for second number

1.4 Store Second Number

Refine Step 2.

2.1 Set total = First Number + Second Number

Refine Step 3.

3.1 Display the sum

3.2 Display total

2. Software Development, Computing Higher

Summer Holidays

June 21, 2011 Mr Stratton

I have been asked loads of times “Sir, what can I do to be prepared for the Higher course?”, the answer is very simple. Download MS Visual Basic Express and LTS’ notes.
Work through the notes during the holidays and you will be well prepared for next year.

1. Computer Systems, 2. Software Development, 3. Multimedia, 6. External Sites, Computing Higher

2007 SQA Past Paper Marking Scheme

May 9, 2011 Mr Stratton

2007 Computing SQA Exam Intro

2007 Computing SQA Exam Section 1

2007 Computing SQA Exam Section 2 Intro

2007 Computing SQA Exam Q 17

2007 Computing SQA Exam Q 18

2007 Computing SQA Exam Q 19

Computing

Category Archives: 2. Software Development

Software Development Revision

Homework for Tue 8th Nov 2011

Dice Roll Program

Module Library

Logical & Syntax Errors

Times Table V2 – Solution

Times Table V1 Design

Step wise refinement.

Summer Holidays

2007 SQA Past Paper Marking Scheme

Coltness High School