A programming presentation for A level students in computer science and software engineering

1. programming
@Saint ….Blessing Nyandoro
Part 1 free treat

2. Requirements of the syllabus
 DESCRIBE THE FEATURES OF HIGH LEVEL LANGUAGE
 LANGUAGE FEATURES OF PROGRAMMING
 PROGRAMMING CONSTRUCTS
 MANIPULATE AN ARRAY
 READ/WRITE TO FILE
 DESIGN INPUT OR OUTPUT INTERFACE
 FEATURES OF OOP (OBJECT ORIENTED PROGRAMMING)
 DESIGN GAMES OR MOBILE APPLICATIONS

3. TYPES OF HIGH LEVEL LANGUAGES
 GENERAL PURPOSE
 SPECIAL PURPOSE
 OBJECT ORIENTED PROGRAMMING
 DECLARATIVE
 IMPERATIVE / PROCEDURAL

5. OBJECT ORIENTED PROGRAMMING
 These languages use object-oriented programming paradigms as the design
approach for solving a given problem. In this programming language, a problem is
divided into a number of objects which can interact by passing messages to each
other. C++ and C# are the examples of object-oriented programming languages
 Class
 Instance
 Object
 Abstraction
 Encalpsulation
 Inheritance
 Polymprphism

6. FEATURES
 CONSTANTS – RESERVED STORAGE
 VARIABLES (LOCAL AND GLOBAL VARIABLES)
 EXPRESSIONS
 STATEMENTS
 CONTROL STRUCTURE
 BLOCK STRUCTURE

7. PROGRAMMING
QUESTIONS

8. Looping structures
 Question: find the average of ten numbers

10. FUNTIONS
 The Function procedure performs a task and then returns control to the calling code. When it returns
control, it also returns a value to the calling code.
 Each time the procedure is called, its statements run.
 [Modifiers] Function FunctionName [(ParameterList)] As ReturnType
 [Statements]
 End Function
 Example:
 Public Function FindSqrt(radicand As Single) As Single
 End Function

11. Calling the function
 lvalue = functionname [( parameterlist )]
 CREATING A FUNCTION HYPOTENUSE
 Function Hypotenuse(side1 As Double, side2 As Double) As Double
 Return Math.Sqrt((side1 ^ 2) + (side2 ^ 2))
 End Function
 CALLING THE FUNCTION HYPOTENUSE
 Private Sub
 Dim testLength, testHypotenuse As Double
 testHypotenuse = Hypotenuse(4, 10.7)

12. inputbox
 Syntax::
 InputBox(prompt[,title][,default][,xpos][,ypos][,helpfile,context])
 InputBox("What is your message?", "Message Entry Form", "Enter your messge here", 500, 700)
 Output:

13. QUESTION INVOLVING INPUTBOX AND
FUNCTION
 Write a program to grade marks for 12 courses for a college student. Use any
selection statement of your choice. The grades are as follows

 >= 75 Distinction
 60-74 Merit
 50-59 Pass
 40-49 Supplementary
 <=39 Fail
[12]

14. PROPERTIES
Control Property
InputBox "Enter mark for Course" & i
Label Name
Text
LblOutput
Answer
Button Name
Text
BtnEnter
Enter Marks

15. INPUT DESIGN

16. CODE
 Public Class Form2

 Private Sub BtnEnter_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
Handles BtnEnter.Click
 Dim output As String = ""

 ‘Loop for entering marks for 12 courses
 For i = 1 To 12
 Dim c As String = InputBox("Enter mark for Course" & i)
 output += "Course" & i & " " & c & " " & Grade(c) + vbNewLine
 Next
 LblOutput.Text = output
 End Sub

 ‘function for calculating grades and outputting grade
 Private Function Grade(ByVal mark As Integer)
 Dim grd As String = ""


17. If mark > 100 Then
grd = "invalïd mark"
ElseIf (mark >= 75) Then
grd = "Distinction"
ElseIf mark >= 60 Then
grd = "Merit"
ElseIf mark >= 50 Then
grd = "Pass"
ElseIf mark >= 40 Then
grd = "Supplementary"
ElseIf mark >= 0 Then
grd = "Fail"
Else
grd = "invalïd mark"
End If
Return grd
End Function
End Class

18. OUTPUT

19. Message box

20. QUESTION involving a message box
b A person invests $1000.00 in a savings account that yields 5% interest. Assuming that all interest is left on deposit, calculate and print the
amount of money in the account at the end of each year over a period of 10 years. To determine these amounts, use the following formula:
a = p (1 + r) n
where
p is the original amount invested (i.e., the principal)
r is the annual interest rate (e.g., .05 stands for 5%)
n is the number of years
a is the amount on deposit at the end of the nth year.
The interface is as below
[20]

21. INPUT DESIGN

22. CODE

23. OUTPUT

24. Palindrome test code
 Interface

25.  CODE:

26. OUTPUTS

28. FILE HANDLING

30. Text files created
 Text Files created
 Filee 1(writing file)
 File 2(read file)
 File 1:

32. output
 Output:
Result in file 2:

33. QUESTIONS TO DISCUSS

34. Csv files
 When reading data from a file, the easiest file type to use is a CSV file, this
stands for comma separated values.
 Each piece of data is separated by a comma. This means that when you split
the information up you can say to the program split the information into the
list every time you find a comma.
 This means you can then refer to elements of the list to extract single pieces
of information. Imagine the array you have is called games, the second image
above shows how you would reference the information. If you wanted the
name of the game it would be games(1), if you wanted to the rating it would
be games(3)

35. Example:

36. THE QUESTION REQUIRES US TO CREATE A
CSV FILE WITH CARS AND THEIR SPEEDS AND
WITH A SPEED LIMIT ENTERED THE CARS
OVERSPEEDING WILL BE DETERMINED AND
OUTPUT ON A WINDOWS APPLICATION FORM

37. DESIGNING THE
CINTROLS
 COMBOBOX: CmbLimit
 LIST BOX: lstOutput
 BUTTON: BtnCheck

38. INTERFACE

39. Code

40. Output:

41. Csv file created

42. DESIGN GAMES OR MOBILE
APPLICATIONS
TOWER OF HANOI

44. MANIPULATING AN ARRAY
• FIRST WE POPULATE THE ARRAY
• THE WE SORT THE ARRAY
 BUBBLE SORT
 QUICK SORT
• SEARCH FOR AN ITEM
 LENEAR SEARCH
 BINARY SEARCH

45. POPULATING AN AREA
 An array in Visual Basic is created in the following way:
 Dim sentence As Array = {"The","quick","grey","fox","jumps"}
 This example creates an array called sentence that has 5 elements to it.
 If you wanted to display the word grey in a message box you would type:
 MessageBox.Show(sentence(2))

46. If you wanted to output the entire contents of the array, you could use a list box and use the
following code:
Dim sentence As Array = {"The","quick","grey","fox","jumps"}
lstOutput.Items.Add(sentence(0))
lstOutput.Items.Add(sentence(1))
lstOutput.Items.Add(sentence(2))
lstOutput.Items.Add(sentence(3))
lstOutput.Items.Add(sentence(4))
You could also use a loop to do the same thing:
Dim sentence As Array = {"The","quick","grey","fox","jumps"}
For x = 0 to sentence.length-1
 lstOutput.Items.Add(sentence(x))
Next