topic 1 – getting started - Lesmahagow High · Web viewThe program will estimate a...

Higher Computing Science

Software Design and Development

Programming with Visual Studio 2012

1

Topic 1 Getting started

Topic 2 Strings and Pre-Defined Functions

Topic 3 Selection

Topic 4 1-D Arrays

Topic 5 User-defined functions

Topic 6 Parameter passing

Topic 7 Standard Algorithms

Topic 8 Reading from a sequential file

Topic 9 Using records

Higher Computing Science 2

CONTENTS

You will have used a variety of different data types in the Nat 5 programming unit. These are:Integer - stores whole numbers

Single - stores real numbers (numbers with a decimal point in them)

String - stores alphanumeric characters (letters / symbols / numbers)

Boolean - stores one of two values: True or False

Task 1: Wages program - Using variables: Real (single)

FORM DESIGN

PROPERTIES

HEADING Label: Name is lblHeading Text is Real Numbers

EXIT Button: Name is cmdExit Text is EXITCLEAR button: Name is cmdClear Text is CLEARSTART button: Name is cmdStart Text is STARTLISTBOX1: Name is listbox1

DESIGN1. Take in pay details2. Calculate wages

Refine Step 1: Take in pay details 1.1 Ask for hourly rate.1.2 Display hourly rate.1.3 Ask for number of hours worked.1.4 Display number of hours worked.

Refine Step 2: calculate wages2.1 Total pay = hourly rate * hours worked2.2 Display total pay

CODE

Public Class Form1


topic 1 – getting started

Program specification – Wages calculator

Design and write a program that asks the user to enter their hourly rate and the number of hours worked. The total pay should be calculated and displayed.

'Task 1: Real Variables ‘program to calculate the total pay from hours worked and work rate 'set the data types of the global variables required in the program Dim hours_per_week, hourly_rate, total_pay As Single

Private Sub cmdStart_Click(sender As Object, e As EventArgs) Handles cmdStart.Click

'main steps to calculate total pay

take_in_details() calculate_wage() End Sub

Private Sub take_in_details() ' Step 1: take in hourly rate and hours worked and convert to a value

hourly_rate = Val(InputBox("Please enter your hourly rate.")) ListBox1.Items.Add("The hourly rate is " & hourly_rate) hours_per_week = Val(InputBox("Please enter your hours worked this week.")) ListBox1.Items.Add("The number of hours worked is " & hours_per_week) End Sub

Private Sub calculate_wage() ' Step 2: calculate and display the total wage total_pay = hourly_rate * hours_per_week

ListBox1.Items.Add("") ' display a blank line ListBox1.Items.Add("The total pay for the week is " & total_pay) End Sub

Private Sub cmdClear_Click(sender As Object, e As EventArgs) Handles cmdClear.Click 'clear the contents of the list box

ListBox1.Items.Clear() End Sub

Private Sub cmdExit_Click(sender As Object, e As EventArgs) Handles cmdExit.Click End End Sub

End Class

Load and run the program called Higher Task1 Real.



OUTPUT

Run your program with the test data below.

You will notice from the output that the total pay is not displayed properly: The pay has 3 decimal places The pay does not have a pound sign

Formatting outputIn your calculate_wage procedure change the line that displays the wage to this:

ListBox1.Items.Add("The total pay for the week is " & Format(total_pay, ".000"))

Copy the table below and adapt your program to the different formats shown. Decsribe the output that each format command produces:

Format Command Description of this functionFormat(average, ".000")

Format(average, "000.0")

Format(average, "###.0")

Format(average, "fixed")

Format(average, "currency")

Format(average, "percent")

Task 2: Ask a question - Using Variables: Boolean



Program specification – Ask a question

Design and write a program that asks the user to enter the answer to a question. The user will be told whether they are correct or wrong.

FORM DESIGN

PROPERTIES

HEADING Label: Name is lblHeading Text is Boolean VariablesEXIT Button: Name is cmdExit Text is EXITCLEAR button: Name is cmdClear Text is CLEARSTART button: Name is cmdStart Text is STARTLISTBOX1: Name is listbox1

DESIGN 1. Ask question()2. Check answer()3. Display result()

Refine Step 1: Ask Question 1.1 set correct to False1.2 ask for answer to question “what is capital of Norway?”.1.3 Display user’s answer

Refine Step 2: check answer is correct2.1 if answer is Oslo 2.2 set correct to True2.3 end if

Refine Step 3: Ask Question 3.1 If correct is True3.2 display “well done” message3.3 Else3.4 Display “wrong” message3.5 End if

CODE

Public Class Form1 'Task 2: program with Boolean value



'Quiz program which asks for the capital of Norway

'set the data types of the global variables required in the program Dim answer As String Dim correct As Boolean


'main steps to calculate total pay Ask_question() Check_answer() Display_message() End Sub

Private Sub ask_question() ' ask the user the question and display their answer correct = False answer = InputBox("What is the capital city of Norway?") ListBox1.Items.Add("The answer you gave is " & answer) ListBox1.Items.Add("") End Sub

Private Sub check_answer() ' check if the users answer is correct If answer = "Oslo" Then correct = True End Sub

Private Sub display_message() ' display an appropriate message to the user If correct = True Then ListBox1.Items.Add("Your answer is correct - well done!") Else ListBox1.Items.Add("Your answer is not correct") End If End Sub

Private Sub cmdClear_Click(sender As Object, e As EventArgs) Handles cmdClear.Click 'clear the contents of the list box ListBox1.Items.Clear() End Sub


End Class

Load and run the program called Higher Task 2 Boolean



OUTPUTRun your program with the test data below:

Task 3: Charity Collection – Procedures and formatting

Create a design for your Form and for your Code. Show this to your teacher before you implement this program.

Typical Inputs and Output



Problem:Three friends have been collecting money for charity. A local company has offered to add a donation based on the total amount they manage to raise. Write a program that allows the friends to enter their individual amounts. The program should then add the three amounts and store the total. The following decisions on the donation from the company are made:

a) any amount raised less than £1000 has a £100 bonus (for example £345 raised = £445 total)

b) the company will double the amount raised between (and including) £1000 and £2000 (for example £1282 raised = £2564 total)

c) if the amount is over £2000 the initial £2000 is doubled but any amount after that is not (for example £2054 raised = 2*£2000 + £54 = £4054 total)

Topic 2 - Working with Strings

Visual Studio provides a number of useful pre-defined functions for manipulating strings.

Name How it works What it does ExampleInput(s) Output

Len String Integer calculates the number of characters in a string

Letters = Len(“blob”) will result inLetters = 4

Ucase String String converts lower-case characters into upper-case characters

String_in = Ucase(“blob”) will result inString_in = “BLOB”

Lcase String String converts upper-case characters into lower-case characters

String_in = Lcase(“XX”) will result inString_in = “xx”

Asc String Integer Returns the ASCII value of a character

Ascii-no = Asc(“A”) will result inAscii_no = 65

Chr Integer String takes an ASCII value and returns the corresponding character

Letter = Chr(65) will result inLetter = “A”

Left StringInteger

String Extracts a sub-string from a string

Part = Left(“Word”, 3) will result in Part = “Wor”

Right StringInteger

String Extracts a sub-string from a string

Part = Right(“Word”, 2) will result in Part = “rd”

Mid StringIntegerInteger

String extracts a sub-string from a string

Part = Mid$(“Word”, 2, 3) will result in Part = “ord”

NOTE: Every function above has one or more inputs to the functions BUT every function has only ONE OUTPUT!!!


TOPIC 2 – STRINGS & PRE-DEFINED FUNCTIONS

Task 4: String functions

FORM DESIGN

PROPERTIES

HEADING Label: Name is lblHeading Text is Pre-Defined String Functions

EXIT Button: Name is cmdExit Text is EXIT

CLEAR button: Name is cmdClear Text is CLEAR

LowerCase button: Name is cmdLower Text is Lower case

UpperCase button: Name is cmdUpper Text is Upper case

Left button: Name is cmd Left Text is Left

Right button: Name is cmdRight Text is Right

Middlebutton: Name is cmdMiddle Text is Middle

Capitalise button: Name is cmdCapFirst Text is Capitalise First

Convert button: Name is cmdConvert Text is Convert first to ASCII

LISTBOX1: Name is listbox1

DESIGN



Program specification

The program will ask the user to enter a name and will then carry out a series of string operations on the name.

Lowercase1. Read in originalname2. Change originalname to lowercase and store in newname3. Display originalname4. Display newname

Uppercase1. Read in originalname2. Change originalname to uppercase and store in newname3. Display originalname4. Display newname

Left1. Read in originalname2. Store the left 2 characters in newname3. Display originalname4. Display newname

Right1. Read in originalname2. Store the right 2 characters in newname3. Display originalname4. Display newname

Middle1. Read in originalname2. Get the length of originalname3. Store the middle two characters in newname4. Display length5. Display originalname6. Display newname



Capitalise First1. Read in originalname2. Get the length of original name3. Store the first character in firstletter4. Store the rest of the characters in restofname5. Make firstletter a capital and store it in capital6. Concatenate the capital and the restofname7. Display length8. Display original name9. Display new name

Convert to Ascii1. Read in originalname2. Store the first character in firstletter3. Convert firstletter to an Ascii value and store it in letterasascii4. Display original name5. Display first letter6. Display first letter as Ascii

CODE

Public Class Form1 'Task 3 : program with pre-defined string functions

'set the data types of the global variables required in the program

Dim originalname, newname, firstletter, restofname, capital As String Dim letterasascii, length As Integer

Private Sub cmdLower_Click(sender As Object, e As EventArgs) Handles cmdLower.Click ' convert the name to lower case letters

originalname = InputBox("Please enter a name") newname = LCase(originalname) ListBox1.Items.Add("the original name is : " & originalname) ListBox1.Items.Add("the new name name is :" & newname) ListBox1.Items.Add("") End Sub

Private Sub cmdUpper_Click(sender As Object, e As EventArgs) Handles cmdUpper.Click ' convert the name to upper case letters

originalname = InputBox("Please enter a name") newname = UCase(originalname) ListBox1.Items.Add("the original name is :" & originalname) ListBox1.Items.Add("the new name name is : " & newname) ListBox1.Items.Add("") End Sub Private Sub cmdLeft_Click(sender As Object, e As EventArgs) Handles cmdLeft.Click ' extract the first character on the left originalname = InputBox("Please enter a name") newname = Microsoft.VisualBasic.Left(originalname, 2)



ListBox1.Items.Add("the original name is : " & originalname) ListBox1.Items.Add("the first two characters are : " & newname) ListBox1.Items.Add("") End Sub

Private Sub cmdRight_Click(sender As Object, e As EventArgs) Handles cmdRight.Click ' extract the last character from the right originalname = InputBox("Please enter a name") newname = Microsoft.VisualBasic.Right(originalname, 2) ListBox1.Items.Add("the original name is : " & originalname) ListBox1.Items.Add("the last two characters are : " & newname) ListBox1.Items.Add("") End Sub

Private Sub cmdMiddle_Click(sender As Object, e As EventArgs) Handles cmdMiddle.Click ' extract the middle two characters of the name originalname = InputBox("Please enter a name") length = Len(originalname) newname = Microsoft.VisualBasic.Mid(originalname, length / 2, 2) ListBox1.Items.Add("The length of the original name is " & length) ListBox1.Items.Add("the original name is : " & originalname) ListBox1.Items.Add("the middle two characters are : " & newname) ListBox1.Items.Add("") End Sub

Private Sub cmdCapFirst_Click(sender As Object, e As EventArgs) Handles cmdCapFirst.Click

' extract the first letter of the name and capitalise it originalname = InputBox("Please enter a name") length = Len(originalname) firstletter = Microsoft.VisualBasic.Left(originalname, 1) restofname = Microsoft.VisualBasic.Right(originalname, length - 1) capital = UCase(firstletter) newname = capital + restofname ListBox1.Items.Add("The length of the original name is " & length) ListBox1.Items.Add("the original name is : " & originalname) ListBox1.Items.Add("The new name with a capital letter is : " & newname) ListBox1.Items.Add("") End Sub

Private Sub cmdConvertASCII_Click(sender As Object, e As EventArgs) Handles cmdConvertASCII.Click

' extract the first character of the name and convert to ASCII

originalname = InputBox("Please enter a name") firstletter = Microsoft.VisualBasic.Left(originalname, 1) letterasascii = Microsoft.VisualBasic.Asc(firstletter) ListBox1.Items.Add("the original name is : " & originalname) ListBox1.Items.Add("The first letter of name is : " & firstletter) ListBox1.Items.Add("The first letter as ASCII is : " & letterasascii) ListBox1.Items.Add("") End SubEnd Class

Load and run the program called Higher Task 4 String functions.



OUTPUTRun your program with the test data below:

Lower case, Upper case, Left , Right:

Middle, Capitalise First, Convert first to ASCII:



Task 5: Devising User IDs – String functions

Pre-defined Numeric FunctionsThere are pre-defined functions that work in a mathematical way. These include:

name what it does example

Rnd generates a random number between 0 and 1 X = Rnd * 10

Int returns the whole number part of a real number

Answer = Int(3.24) returnsAnswer = 3

Round Rounds a value to a specified number of decimal places

Answer = Round(3.24, 1) returnsAnswer = 3.2

Val Is used to convert a string to a numeric value Number=Val(txtInput.text)



Problem:A program is required which will automatically generate a password from information provided by the user. The program should generate the password from the first letter of their first name, second letter of their surname, last two letters of their birth month converted to upper case, second and third letters of their favourite colour, first 3 letters of their street name, the second-last character in their name then converted to an ASCII value and finishing with the letters VB.

For example, Brenda McSporran, born in NovembER, likes the colour green lives in Market Place, second last letter is a and converted to 97,

so her password will be BcERreMar97VB.


Task 6: Using Pre-defined Numeric Functions

FORM DESIGN

PROPERTIES

HEADING Label: Name: lblHeading Text: Pre-Defined Numeric Functions

EXIT Button: Name: cmdExit Text: EXIT

CLEAR button: Name: cmdClear Text: CLEAR

Random button: Name: cmdRandom Text: Random Number

Int button: Name: cmdInt Text: Int

Roundbutton: Name: cmdRound Text: Round

ListBox: Name: listbox1



Problem specificationCreate a program which will generate a random number. The program will use the INT function on a random number and also the ROUND function.

DESIGN

Random Number1. Generate random number2. Display random number3. Display blank line

Int1. Generate random number2. Apply INT function to remove decimal part of random number and store

as result3. Display random number4. Display result5. Display blank line

Round1. Generate random number2. Apply ROUND function to round random number to one decimal place

and store as result3. Display random number4. Display result5. Display blank line



CODE

Public Class Form1 'Task 4: program with pre-defined maths functions

Dim randomnumber, result As Single

Private Sub cmdRandom_Click(sender As Object, e As EventArgs) Handles cmdRandom.Click ' generate a random number between 0 and 1

Randomize() randomnumber = Microsoft.VisualBasic.Rnd() ListBox1.Items.Add("the random number generated was : " & randomnumber) ListBox1.Items.Add("") End Sub

Private Sub cmdInt_Click(sender As Object, e As EventArgs) Handles cmdInt.Click 'remove the decimal part of a number

Randomize() randomnumber = Microsoft.VisualBasic.Rnd() * 10 result = Int(randomnumber) ListBox1.Items.Add("the random number multiplied by 10 is : " & randomnumber) ListBox1.Items.Add("INT converts this number to : " & result) ListBox1.Items.Add("") End Sub

Private Sub cmdRound_Click(sender As Object, e As EventArgs) Handles cmdRound.Click 'round a random number to one decimal place

Randomize() randomnumber = Microsoft.VisualBasic.Rnd() result = Math.Round(randomnumber, 1) ListBox1.Items.Add("the random number generated was : " & randomnumber) ListBox1.Items.Add("Rounded to one decimal place : " & result) ListBox1.Items.Add("") End Sub

Private Sub cmdClear_Click(sender As Object, e As EventArgs) Handles cmdClear.Click ListBox1.Items.Clear()

End SubEnd Class

Load and run Higher Task 6 Maths Functions.



OUTPUT

Run your program a few times like the test runs below.

Task 7: Painting a fence – Procedures, rounding and formatting



Problem:The program should calculate the number of tins of paint to paint a rectangular fence and the total cost of buying the tins. The user should enter the dimensions of the fence (the length and height in metres), the cost of one tin of paint and the coverage factor for one tin of paint (how many metres squared can be painted). Both the front and the back of the fence will need to be painted.The program should display the following details:

The total area to be painted (to one decimal place) The number of tines required (rounded up to a whole number) The total cost of buying the tins (formatted as currency).


Topic 3 - Selection using CASE

A Case statement is an alternative to using multiple IF statements. This method has the same outcome but requires less code and is easier to read.

Task 8: Assign a grade – Case statement

FORM DESIGN

PROPERTIES

HEADING Label: Name: lblHeading Text: Case Statement



START button: Name: cmdStart Text: START

LISTBOX1: Name: listbox1



Problem specification

Design and write a program that asks the user to enter their mark. A grade is assigned as follows:-80 or over is a grade 1, 60 to 79 is a grade 2, 40 to 59 is a grade 3, 20 to 39 is a grade 4, 10 to 19 is a grade 5, less than 10 is a grade 6. The grade should be displayed.

TOPIC 3 - SELECTION

DESIGN – MAIN STEPS1. Take in mark()2. Display grade()

DESIGN - REFINEMENTS

Refine Step 1: Take in Mark () 1.1 Read in the pupils mark1.2 In the case of mark1.3 Greater than or equal to 801.4 Grade is 11.5 Greater than or equal to 601.6 Grade is 21.7 Greater than or equal to 401.8 Grade is 31.9 Greater than or equal to 201.10 Grade is 41.11 Greater than or equal to 101.12 Grade is 51.13 Less than 101.14 Grade is 61.15 End Case Statement

Refine Step 2: Display Grade () 2.1 Display the mark2.2 Display the grade2.3 Display a blank line



TOPIC 3 - SELECTION

CODE

Public Class Form1 'task 3.1 Using a case statement to decide on a student grade

Dim mark, grade As Integer

Private Sub cmdStart_Click(sender As Object, e As EventArgs) Handles cmdStart.Click take_in_mark() display_grade() End Sub Private Sub take_in_mark() ' ask user to enter the mark out of 100 mark = Val(InputBox("Please enter pupil's mark out of 100"))

'decide on an appropriate grade Select Case mark Case Is >= 80 grade = 1 Case Is >= 60 grade = 2 Case Is >= 40 grade = 3 Case Is >= 20 grade = 4 Case Is >= 10 grade = 5 Case Is < 10 grade = 6 End Select End Sub

Private Sub display_grade() ' display the pupil's mark and grade ListBox1.Items.Add("The pupil's mark is " & mark) ListBox1.Items.Add("Their grade is " & grade) ListBox1.Items.Add("") End SubEnd ClassOUTPUTTest your program with sample output similar to below:

Load and run Higher Task 8 Assign a grade.



TOPIC 3 - SELECTION

Task 9: Posting a Package – Case statementDesign, implement and test a program to calculate the cost of posting a package by first class mail, based on the following table:


Theory Task 1: Error detectionAsk your teacher for a printed copy of this task.



TOPIC 3 - SELECTION

Weight up to and including:

Cost

100g 42p300g 99p450g £1.68600g £2.03800g £2.73900g £3.101000g £3.45each extra 250g add 86p

Topic 4: Arrays

Task 10: Store 10 marks - Fill an array using a For Loop

FORM DESIGN

PROPERTIES

HEADING Label: Name: lblHeading Text: Fill an Array






TOPIC 4 - ARRAYS


Design and write a program that asks the user to enter 10 marks. The marks should then be displayed.

DESIGN

1. Take in Marks()2. Display Marks()

Refine Step 1 Take in Marks1.1 repeat 10 times1.2 read in current mark into correct location in array1.3 end loop

Refine Step 2 Display Marks2.1 Display heading2.2 Display blank line2.3 Repeat 10 times2.4 Display current mark2.5 End loop

CODE

Public Class Form1 ' Topic 4: Filling a array within a fixed loop

Dim mark(9) As Integer Dim pupil As Integer

Private Sub cmdStart_Click(sender As Object, e As EventArgs) Handles cmdStart.Click 'main steps of the problem

take_In_Marks() display_marks()

End Sub

Private Sub take_in_marks() 'ask for 10 marks

For pupil = 0 To 9 mark(pupil) = Val(InputBox("Please enter the mark for pupil " & pupil + 1)) Next pupil

End Sub

Private Sub display_marks() 'display the marks in the listbox

ListBox1.Items.Add("Here are the marks for the class") ListBox1.Items.Add("") For pupil = 0 To 9 ListBox1.Items.Add("Pupil " & pupil + 1 & "- mark is " & mark(pupil)) Next pupil

End SubEnd Class

Load and run the program called Higher Task 10 Fill an array.

OUTPUT


TOPIC 4 - ARRAYS

Theory Task 2: Error detectionAsk your teacher for a printed copy of this task.

Task 11: Lottery Winner – Using arrays & RND function.

Problem Specification

Design, implement and test a program to do the following:

The program should prompt the user to enter 10 names and 4 different prizes.

The program should select a lucky winner at random and assign them a prize also chosen at random.

The program should display all ten possible winners and all 4 possible prizes. It should also display the name of the winner and the chosen prize.

Create a design for your Form and for your Code. Show this to your teacher before you implement this program


TOPIC 4 - ARRAYS

Topic 5: Parameter PassingThis section of the course shows algorithms including data flow as well as programs that use procedures.

Data Flow:In/out is the equivalent of ByRef In is the equivalent of ByVal

Task 12: Area of a rectangle – Parameter passing

FORM DESIGN

PROPERTIES

HEADING Label: Name: lblHeading Text: Area of a rectangle






topic 1 – getting startedPASSING


Design and write a program that asks the user to enter a length and a breadth of a rectangle. The area of the rectangle is calculated and then displayed.

TOPIC 5 – PARAMETER PASSINGTOPIC 5 – PARAMETER PASSING

DESIGN – MAIN STEPS

1 get values from user() in/out: length, breadth2 calculate the area() in: length, breadth in/out: area3 display the area() in: area

CODE DESIGN – REFINEMENTS

refine step 1 get values from user in/out: length, breadth

1.1 Read in the length1.2 Display the length1.3 Read in the breadth1.4 Display the breadth

refine step 2 calculate the area in: length, breadth in/out: area

2.1 multiply length by breadth to give area

refine step 3 display the area in: area

1.1 display a blank line1.2 display a message to the use giving the area



TOPIC 5 – PARAMETER PASSING

CODE

Public Class Form1 ' this program calculates the area of a rectangle using parameter passing

Private Sub cmdStart_Click(sender As Object, e As EventArgs) Handles cmdStart.Click 'the main steps of the problem

‘declare the parameter data types Dim length, breadth, area As Single

getvalues(length, breadth) calculatearea(length, breadth, area) displayarea(area) End Sub

Private Sub getvalues(ByRef length, ByRef breadth) ' ask the user to enter the dimensions of the rectangle

length = Val(InputBox("Please enter the length of the rectangle (in centimetres)"))

ListBox1.Items.Add("The length is " & length & "cm") breadth = Val(InputBox("Please enter the breadth of the rectangle (in

centimetres)")) ListBox1.Items.Add("The breadth is " & breadth & "cm") End Sub

Private Sub calculatearea(ByVal length, ByVal breadth, ByRef area) ' this module will calculate the area

area = length * breadth End Sub

Private Sub displayarea(ByVal area) ' this module will display the area

ListBox1.Items.Add("") ListBox1.Items.Add("The area of the rectangle is " & area & "cm squared") End SubEnd Class

Load and run Higher Task 12 Area of a rectangle.

OUTPUTTest your program with sample output similar to below:




Task 13: Estimate Grades – Parameter passing



The program will estimate a pupil’s grade for their Nat5 Computing Science exam based on a mark from their prelim and their coursework total. Their prelim mark is out of 90 and their coursework is out of 60. The total is converted to a percentage and the following estimates are applied:

>= 85% = Band 1>= 70% = Band 2>= 65% = Band 3>= 60% = Band 4>= 55% = Band 5>= 50% = Band 6>= 45% = Band 7<45% = Band 8

Your program should display the total mark out of 150, their percentage and their Band estimate.

Create a design for your Form and for your Code showing the data flow for the problem. Show this to your teacher before you implement this program.




Topic 6: User-defined FunctionsPre-defined functions (like LEN) are already made for us. If we want to create a function we will use again and again, we create a user-defined function.

Functions can input several parameters but only ever return one value . Functions are different from procedures that can input several parameters and may also return many parameters.

Task 14: Calculate an area – Using a function

FORM DESIGN

PROPERTIES

HEADING Label: Name: lblHeading Text: Area of a circle (user-defined Function)






1. get radius() in/out: radius2. calculate and display the area() in: radius

CODE DESIGN – REFINEMENTS

Refine step 1 get radius from user in/out: radius1.1 Read in the radius1.2 Display the radius

Refine step 2 calculate and display the area in: radius


TOPIC 6 – USER-DEFINED FUNCTIONS


Design and write a program that asks the user to enter the radius of a circle. The area is then calculated and displayed.

2.1 calculate area2.2 display area

Refine Function: get Area display the area in: radius1. area = radius ^ 2 * 3.142. return area

CODE

Public Class Form1 'this program calculates the area of a circle 'this version uses a user-defined function to calculate the area

Private Sub cmdStart_Click(sender As Object, e As EventArgs) Handles cmdStart.Click 'this contains the main steps of the problem 'declare parameter data type Dim radius As Single

get_radius(radius) calculate_and_display(radius) End Sub

Private Sub get_radius(ByRef radius) ' this module will ask the user to enter the radius

radius = Val(InputBox("Please enter the radius of the circle in cm")) ListBox1.Items.Add("The radius of the circle is " & radius & "cm") End Sub

Private Sub calculate_and_display(ByVal radius) Dim area As Single area = get_area(radius) ListBox1.Items.Add("The area is " & area & "cm squared") End Sub

Function get_area(Radius) As Single Dim area As Single area = math.Round(Radius ^ 2 * 3.14,2) Return area End FunctionEnd Class

Load and run Higher Task 14 Area using function.

OUTPUTTest your program with the following test data:

Test Type of Test

Test data Expected Result

1 Normal Radius = 5 Area = 78.5

2 Normal Radius = 6.7 Area = 140.95

3 Extreme Radius = 23.78 Area = 1775.63



Task 15: Input Validation Function

FORM DESIGN

PROPERTIES

HEADING Label: Name: lblHeading Text: Validation using a Function






1 get_numbers() in/out: num1, num22 calculate and display total() in: num1, num2

DESIGN – REFINEMENTS

Refine step 1 get numbers in/out: num1, num21.1 Validate number 1 using function1.2 Validate number 2 using function




Design a program which will ask the user to enter two numbers between 1 and 10. The program will then find the sum of these numbers. Inputs from the user must be validated.

Refine step 2 calculate and display total in: radius 2.1 calculate sum of number 1 and number 2 2.2 calculate and display answer

Refine Function: get valid number in: prompt, low, high out: number1. ask the user to enter a number between low and high2. Loop while the number is less than low or greater than high3. Display an error message to the user4. Ask the user to re-enter the number5. End loop6. return number

CODE Public Class Form1 'program using a function to validate inputs from user

Private Sub cmdStart_Click(sender As Object, e As EventArgs) Handles cmdStart.Click 'declare data flow parameters Dim num1, num2 As Integer 'main steps get_values(num1, num2) calculate_and_display_total(num1, num2) End Sub

Private Sub get_values(ByRef num1, ByRef num2) 'procudeure to input numbers from user num1 = get_valid_number("Please enter a number between ”, 1, 10)) num2 = get_valid_number("Please enter a number between ”, 1, 10)) End Sub

Private Sub calculate_and_display_total(ByVal num1, ByVal num2) 'procedure to calculate and display values 'declare local variable Dim answer As Integer answer = num1 + num2 ListBox1.Items.Add(num1 & " + " & num2 & " = " & answer) End Sub

Function get_valid_number(byval prompt, byval low, byval high) As Integer 'function used to validate a number between 2 boundaries Dim number as integer number = Val(InputBox(prompt & low & “ and ” & high)) Do While number < low Or number > high MsgBox("That number is invalid. Please try again") number = Val(InputBox(prompt & low & “ and ” & high)) Loop Return number End FunctionEnd Class

Load and run Higher Task 15 Input Validation

OUTPUTTest your program with the following test data:



Test Type of Test


1 Normal Num1 = 4 num2 = 7 4 + 7 = 11

2 Normal Num1 = 8 num2 = 5 8 + 5 = 13

3 Extreme Num1 = 1 num2 = 10 1 + 10 = 11

4 Extreme Num1 = 2 num2 = 9 2 + 9 + 11

5 Exceptional Num1 = 14 num2 = 7 Error message for num1

6 Exceptional Num1 = 4 num2 = 78 Error message for num2

Task 16: Input Validation – User defined functionsProblem specification


The user should enter 3 different values and each should be validated as shown:

I. prompt the user to enter either a ‘yes’ or a ‘no’. the program should also accept ‘yes’, ‘no’, ‘yeS’, ‘NO, ’nO’ etc…

II. prompt the user to enter a telephone number. The program should only accept a number starting with the digit ‘0’ and with a total of 11 digits. Assume no spaces are allowed.

III. Prompt the user to enter a password which can include any character except for a space, and must be more than 6 characters long.




Topic 7: Standard Algorithms

In the design and development of software, there are certain tasks which are needed over and over again. For example, almost every program uses input validation to prevent a user entering data which cannot be acceptable and which might cause the program to fail.

Rather than every programmer having to write the code for an input validation routine, this module of code can be taken from a module library to be re-used or adapted.

There are many other standard algorithms, including: Finding the maximum value Finding the minimum value Linear Search Counting Occurrences

Task 17: Highest Mark – find maximum algorithm

Task 17: Finding the Maximum Value

FORM DESIGN

PROPERTIES

HEADING Label: Name: lblHeading Text: Findinf the Maximum





TOPIC 7 – STANDARD ALGORITHMS


Design and write a program that generates 5 random marks between 1 and 100 and stores them in an array. The marks are displayed then the highest mark is displayed.


1. initialise variables() in/out: max, marks_array2. fill array with data () in/out: marks_array3. display the array in: marks_array 4. find the maximum value in: marks_array in/out: max 5. display max in: max


Refine step 1 initialise variables() in/out: max, marks_array1.1 clear contents of list box1.2 start loop counter from 0 to 41.3 set marks_array (loop counter) to 01.4 End loop1.5 Set max to 0

Refine step 2 fill array with data () in/out: marks_array

2.1 start loop counter from 0 to 42.2 set marks_array (loop counter) to a random value between 1 and 1002.3 End loop

Refine step 3 display the array in: marks_array

3.1 display title “Here are the marks:”3.2 display a blank line3.3 start loop counter from 0 to 43.4 display marks_array (loop counter)3.5 End loop

Refine step 4 find the maximum value in: marks_array in/out: max

3.1 set max to equal the first element in the array3.2 start loop for the rest of the array3.3 If marks_array (loop counter) is greater than max then3.4 set max to equal marks_array (loop counter)3.5 End If 3.6 End loop

Refine step 4 display max in: max

3.1 Display a blank line3.2 Display “The highest mark is “ and max



CODE Public Class Form1 'Standard Algorithm task - Find the max

Private Sub cmdStart_Click(sender As Object, e As EventArgs) Handles cmdStart.Click 'contains the main steps of the problem

'declare the parameters Dim marks_array (4) As Integer Dim max As Integer Randomize()

initialise(max, marks_array) fill_random_marks(marks_array) display_array(marks_array) find_max(max, marks_array) display_maximum(max) End Sub

Private Sub initialise(ByRef max, ByRef marks_array) ' this module sets an initial value to the parameters

Dim index As Integer ListBox1.Items.Clear() For index = 0 To 4 marks_array(index) = 0 Next max = 0 End Sub

Private Sub fill_random_marks(ByRef marks_array) ' this module will populate the array with random marks between 1 and 100

Dim index As Integer For index = 0 To 4 marks_array(index) = Int(Microsoft.VisualBasic.Rnd() * 100) + 1 Next End Sub

Private Sub display_array(ByRef marks_array) 'this module will display the random marks

Dim index As Integer

ListBox1.Items.Add("Here are the marks:”) ListBox1.Items.Add("") For index = 0 To 4 ListBox1.Items.Add(marks_array(index)) Next End Sub



Private Sub find_max(ByRef max, ByRef marks_array) ' this module will find the highest mark in the array Dim index As Integer

max = marks_array(0) For index = 1 To 4 If marks_array(index) > max Then max = marks_array(index) End If Next End Sub

Private Sub display_maximum(ByVal max) ' this module will display the highest mark

ListBox1.Items.Add("") ListBox1.Items.Add("The highest marks is ” & max) End SubEnd Class

Load and run Higher Task 17 Highest mark.

OUTPUTTest your program works by running it a few times. Ensure the following works correctly:

The program picks up the correct value each time The program is correct when the max value is the first item in the array



Task 18: Find the Min and Max temperatureProblem specification


The program should ask the user to enter the average temperature that occurred each day for one week. The program will display these temperatures and then display the highest and lowest temperature for the week.

Example:Day 1: 12 degreesDay 2: 10 degreesDay 3: 17 degreesDay 4: 6 degreesDay 5: 18 degreesDay 6: 9 degreesDay 7: -6 degrees

Highest temperature was 18 degrees Lowest temperature was -6 degrees


Task 19: Find the days that had the min and max temperature


Improve your last program so that it displays output like this:-

Sunday: 12 degreesMonday: 10 degreesTuesday: 17 degreesWednesday: 6 degreesThursday : 18 degreesFriday: 9 degreesSunday: -6 degrees

Highest temperature was 18 degrees on ThursdayLowest temperature was -6 degrees on Sunday




Task 20: Mark Counter - Count OccurrencesProblem specification

Design and write a program that asks the user to enter 10 marks between 0 and 100. The marks should be displayed then the user should be asked to enter a target mark that they want to count the occurrences of. The number of times that the target mark appears in the array should be displayed.

FORM DESIGN

PROPERTIES

HEADING Label: Name: lblHeading Text: Findinf the Maximum







1. initialise variables in/out: marks_array, target, counter2. take in marks in/out: marks_array3. target = validated number in: prompt, low, high in/out: target 4. count occurrences of target in: target, marks_array, in/out: counter 5. display results in: marks_array, target, counter


Refine step 1 initialise variables() in/out: marks_array, target, counter1.1 start loop counter from 0 to 91.2 set marks_array(loop counter) to 01.3 End loop1.4 Set counter to 01.5 Set target to 0

Refine step 2 take in marks in/out: marks_array2.1 start loop counter from 0 to 92.2 marks_array(loop counter) = validated number (use get_valid_number function)2.3 End loop

Refine step 3: Function: get valid number in: prompt, low, high out: number1. ask the user to enter a number between low and high2. Loop while the number is less than low or greater than high3. Display an error message to the user4. Ask the user to re-enter the number5. End loop6. return number

Refine step 4 count occurrences of target in: target, marks_array, in/out: counter 4.1 start loop counter from 0 to 94.2 If marks_array(loop counter) = target4.3 add 1 to counter4.4 End If statement4.5 End loop

Refine step 5 display results in: marks_array, target, counter

5.1 Display “Here are the marks “5.2 Start loop counter from 0 to 95.3 Display marks_array(loop counter)5.4 End loop5.5 Display a blank line5.6 Display “The target being counted is ” and target5.7 Display “it was found “ and counter and “times”

CODE Public Class Form1 ' Standard algorithms task - Count Occurences of a value in a list




'declare the parameters used Dim marks_array(9) As Integer Dim target, counter As Integer

'main steps of the problem initialise(marks_array, target, counter) take_in_marks(marks_array) target = get_valid_number("What mark do you want to search for? Enter a

mark between ”, 0, 100)

count_occurences(marks_array, target, counter) display_results(marks_array, target, counter) End Sub

Private Sub initialise(ByRef marks_array, ByRef target, ByRef counter) 'set an initial value to all parameters used in the program

Dim index As Integer For index = 0 To 9 marks_array(index) = 0 Next counter = 0 target = 0 End Sub

Private Sub take_in_marks(ByRef marks_array) 'populate the array with valid marks from the user

Dim index As Integer For index = 0 To 9 marks_array(index) = get_valid_number("please enter the mark for pupil " &

index + 1, 1, 100)

Next End Sub

Function get_valid_number(byval prompt, byval low, byval high) As Integer 'function used to validate a number between 2 boundaries

Dim number as integer number = Val(InputBox(prompt & low & “ and ” & high))

Do While number < low Or number > high MsgBox("That number is invalid. Please try again") number = Val(InputBox(prompt & low & “ and ” & high)) Loop

Return number End Function

Private Sub count_occurences(ByRef marks_array, ByVal target, ByRef counter)



'count how many times the target appears in the list

Dim index As Integer For index = 0 To 9 If marks_array(index) = target Then counter = counter + 1 End If Next End Sub

Private Sub display_results(ByRef marks_array, ByVal target, ByVal counter) 'display the marks entered, the targer being searched for and the number of occurrences Dim pupil As Integer

ListBox1.Items.Add("Here are the marks:") For index = 0 To 9 ListBox1.Items.Add(marks_array(index)) Next ListBox1.Items.Add("") ListBox1.Items.Add("The target being counted is :" & target) ListBox1.Items.Add("It was found " & counter & " times")

End Sub

End Class

Load and run Higher Task 20 Count Occurrences.

OUTPUT

Test your program with the following test data:



Test Type of Test


1 Normal 15,45,47,45,89,62,36,34,45,25

TARGET = 45Target of 45 appears 3 times

2 Normal 15,95,47,45,89,62,36,34,55,25


3 Extreme 45,45,45,45,45,45,45,45,45,45


4 Extreme 0,0,1,1,99,99,100,100,0,100


5 Exceptional Enter mark below 0 and over 100 Error message for mark

6 Exceptional Enter target below 0 and over 100 Error message for target

Task 21: Count the number of days that were a target temperature – Count Occurrences


Improve your temperature program so that it also asks the user to enter a target temperature and displays output like this:-


Highest temperature was 18 degrees on ThursdayLowest temperature was -6 degrees on SundayThe number of days that it was 10 degrees was 2 .




Task 22: Who got a target mark - Linear searchProblem specification

Design and write a program that fills an array with 10 marks then asks the user to enter a target mark. The program should then display the number of each pupil who got the target mark.

FORM DESIGN

PROPERTIES

Property Property

HEADING Label: Name: lblHeading Text: Linear Search







1. initialise variables() in/out: target2. display marks () in: marks_array3. target = validated number in: prompt, low, high out: target4. linear search in: marks_array, target DESIGN – REFINEMENTS

Refine step 1 initialise variables() in/out: target

1.1 clear the contents of the listbox1.2 Set target to 0

Refine step 2 display marks in: marks_array

2.1 Display “Here are the marks”2.2 Display a blank line2.3 start loop counter from 0 to 92.4 display the pupils mark2.5 end loop

Refine step 3: Function: get valid number in: prompt, low, high out: number1. ask the user to enter a number between low and high2. Loop while the number is less than low or greater than high3. Display an error message to the user4. Ask the user to re-enter the number5. End loop6. return number

Refine step 4 linear search in: marks_array, target

4.1 set flag to false4.2 Display a blank line4.3 Start loop from 0 to 94.4 If the value in marks_array(loop counter) = target4.5 Display the position of this target – loop counter4.6 Set flag to true4.7 End if statement4.8 End loop4.9 If flag is false display “Target not found in list”



CODE Public Class Form1 ' Standard Algorithms - Linear Search

Private Sub cmdStart_Click(sender As Object, e As EventArgs) Handles cmdStart.Click ' declare parameters and initialise array with values Dim marks_array() As Integer = {10, 15, 14, 13, 9, 14, 12, 18, 9, 10} Dim target As Integer

initialise(target) display_marks(marks_array) target = get_valid_number("What mark do you want to search for? Enter a

number between ", 0, 20))

linear_search(marks_array, target) End Sub

Private Sub initialise(ByRef target) 'this module will set an initial value for the target ListBox1.Items.Clear() target = 0 End Sub

Private Sub display_marks(marks_array) 'this module will display the values stored in the array Dim index As Integer ListBox1.Items.Add("Here are the marks out of 20:") ListBox1.Items.Add("") For index = 0 To 9 ListBox1.Items.Add("Pupil " & index + 1 & ": " & marks_array(index)) Next End Sub

Private Sub linear_search(ByRef marks_array, ByVal target) 'this module will search the array for occurences of the target value and report their position Dim index As Integer Dim found As Boolean found = False ListBox1.Items.Add("") For index = 0 To 9 If marks_array(index) = target Then ListBox1.Items.Add("The target of " & target & " was found for pupil " & index + 1) found = True End If Next If found = False Then ListBox1.Items.Add("Target " & target & " not found in the list") End Sub

Function get_valid_number(byval prompt, byval low, byval high) As Integer 'function used to validate a number between 2 boundaries

Dim number as integer number = Val(InputBox(prompt & low & “ and ” & high))

Do While number < low Or number > high MsgBox("That number is invalid. Please try again") number = Val(InputBox(prompt & low & “ and ” & high)) Loop

Return number End Function



End Class

Load and run Higher Task 22 Linear search.

OUTPUTYour output should look like this:

Adapt your program to work with the following test data:

Test Type of Test


1 Normal 11, 12, 10, 12, 10, 19, 18, 20, 12, 8

TARGET = 12

Target appears for pupil 2Target appears for pupil 4Target appears for pupil 9

2 Normal 11, 12, 10, 12, 10, 19, 18, 20, 12, 8

TARGET = 10

Target appears for pupil 3Target appears for pupil 5

3 Extreme 11,11,11,11,11,11,11,11,11,11

TARGET = 20Target 20 not on the list

4 Extreme 0,0,1,1,9,9,10,20,10,18

TARGET = 0Target appears for pupil 1Target appears for pupil 2

5 Exceptional0,0,1,1,9,9,10,20,10,18

TARGET = -3Error message for target

6 Exceptional0,0,1,1,9,9,10,20,10,18

TARGET = 21Error message for target



Task 23: Search for the days that were a target temperature


Improve your temperature program so that it also displays the days that matched the target temperature. It should display output like this:-


Highest temperature was 18 degrees on ThursdayLowest temperature was -6 degrees on SundayThe number of days that it was 10 degrees was 2. It was 10 degrees on Monday.It was 10 degrees on Wednesday.



Topic 8 – Reading from a sequential file

Task 24: Read hotel data from a Comma Separated Value file and store it in arrays


Design and create a program that reads data from a file and stores it in arrays.

The output should look like this:-

The Comma Separated Value file looks like this:-


TOPIC 8 – READING FROM A SEQUENTIAL FILE


1. initialize in/out: hotelName, hotelRating, hotelCity,hotelPricePerNight, hotelMealsIncluded, countOfHotels

2. read_file_into_records() in/out: hotelName, hotelRating, hotelCity,hotelPricePerNight, hotelMealsIncluded, countOfHotels

3. display_records() in: hotelName, hotelRating, hotelCity,hotelPricePerNight, hotelMealsIncluded, countOfHotels


Refine step 1 initialise in/out: hotelName, hotelRating, hotelCity, hotelPricePerNight, hotelMealsIncluded, countOfHotels1.1 start loop counter from 1 to 51.2 set hotelName(loop counter) to “”1.3 set hotelRating(loop counter) to 01.4 set hotelCity(loop counter) to “”1.5 set hotelPricePerNight(loop counter) to 01.6 set hotelMealsIncluded(loop counter) to “”1.7 end loop1.8 set countOfHotels to 0

Refine step 2 read_file_into_arrays() in/out: hotelName, hotelRating, hotelCity, hotelPricePerNight, hotelMealsIncluded, countOfHotels2.1 Using myReader to Open a file to read from it2.2 set countOfHotels to 02.3 loop while not at the end of the data2.4 try 2.5 set currentRow to a line in the file2.6 add 1 to countOfHotels2.7 set allHotels(countOfHotels).hotelName field to string 0 in the current line2.8 set allHotels(countOfHotels). hotelRating field to value 1 in the current line2.9 set allHotels(countOfHotels). hotelCity field to string 2 in the current line2.10 set allHotels(countOfHotels). hotelPricePerNight field to value 3 in the

current line2.11 set allHotels(countOfHotels). hotelMealsIncluded field to string 4 in the

current line2.12 Catch file error2.13 display error message2.1 end try2.1 end loop2.1 End Using2

Refine step 3 display_records() in/out: hotelName, hotelRating, hotelCity,



hotelPricePerNight, hotelMealsIncluded, countOfHotels

3.1 start loop counter from 1 to countOfHotels3.2 send allHotels(loop counter).hotelName to display3.3 send allHotels(loop counter).hotelRating to display3.4 send allHotels(loop counter).hotelCity to display3.5 send allHotels(loop counter).hotelPricePerNight to display3.6 send allHotels(loop counter).hotelMealsIncluded to display3.7 end loop

------------------------------------------------------------------------------------------

Public Class Form1


Dim hotelName(5) As String Dim hotelRating(5) As Integer Dim hotelCity(5) As String Dim hotelPricePerNight(5) As Single Dim hotelMealsIncluded(5) As String Dim countOfHotels As Integer

initialise(hotelName, hotelRating, hotelCity, hotelPricePerNight, hotelMealsIncluded, countOfHotels)

read_file_into_arrays(hotelName, hotelRating, hotelCity, hotelPricePerNight, hotelMealsIncluded, countOfHotels)

display_arrays(hotelName, hotelRating, hotelCity, hotelPricePerNight, hotelMealsIncluded, countOfHotels)

End Sub------------------------------------------------------------------------------------------ Private Sub initialise(ByRef hotelName, ByRef hotelRating, ByRef hotelCity, ByRef hotelPricePerNight, ByRef hotelMealsIncluded, ByRef countOfHotels) Dim index As Integer

For index = 1 To 5 hotelName(index) = "" hotelRating(index) = 0 hotelCity(index) = "" hotelPricePerNight(index) = 0 hotelMealsIncluded(index) = "" Next countOfHotels = 0

End Sub------------------------------------------------------------------------------------------



Private Sub read_file_into_arrays(ByRef hotelName, ByRef hotelRating, ByRef hotelCity, ByRef hotelPricePerNight, ByRef hotelMealsIncluded, ByRef countOfHotels) 'reads a comma separated value file into 5 arrays Using MyReader As New Microsoft.VisualBasic.FileIO.TextFieldParser("N:\Visual Studio 2012\Hotel Info.csv")

MyReader.TextFieldType = FileIO.FieldType.Delimited MyReader.SetDelimiters(",")

Dim currentRow As String() ' Dim numberOfFields As Integer

While Not MyReader.EndOfData Try

currentRow = MyReader.ReadFields()

'numberOfFields = currentRow.GetUpperBound(0) ' MsgBox(numberOfFields)

countOfHotels = countOfHotels + 1

hotelName(countOfHotels) = currentRow(0).ToString hotelRating(countOfHotels) = Val(currentRow(1).ToString) hotelCity(countOfHotels) = currentRow(2).ToString hotelPricePerNight(countOfHotels) = Val(currentRow(3).ToString) hotelMealsIncluded(countOfHotels) = currentRow(4).ToString

Catch ex As Microsoft.VisualBasic. FileIO.MalformedLineException MsgBox("Line " & ex.Message & "is not valid and will be skipped.") End Try

End While End Using End Sub------------------------------------------------------------------------------------------

Private Sub display_arrays(ByRef hotelName, ByRef hotelRating, ByRef hotelCity, ByRef hotelPricePerNight, ByRef hotelMealsIncluded, ByVal countOfHotels)

For index = 1 To countOfHotels ListBox1.Items.Add(hotelName(index)) ListBox2.Items.Add(hotelRating(index)) ListBox3.Items.Add(hotelCity(index)) ListBox4.Items.Add(hotelPricePerNight(index)) ListBox5.Items.Add(hotelMealsIncluded(index)) Next

End Sub

Private Sub cmdExit_Click(sender As Object, e As EventArgs) Handles cmdExit.Click End End SubEnd Class

Copy the CSV file called Hotel Info into your Visual Studio 2012 folder. Load and run Higher Task 24 Read a hotel file into arrays.



Task 25: Notice the difference here – actual and formal parameter can have different names

Load and run Higher Task 25 Read a hotel file into arrays using standard modules.

Public Class Form1

Private Sub cmdStart_Click(sender As Object, e As EventArgs) Handles cmdStart.Click 'This module contains the main program





End Sub------------------------------------------------------------------------------------------

Private Sub initialise(ByRef hotelName, ByRef hotelRating, ByRef hotelCity, ByRef hotelPricePerNight, ByRef hotelMealsIncluded, ByRef countOfHotels) 'This module will initialise the records so that the string fields are set to "" and the numeric fields, countOfHotels and are set to 0 Dim index As Integer


End Sub

------------------------------------------------------------------------------------------



Private Sub read_file_into_arrays(ByRef array1, ByRef array2, ByRef array3, ByRef array4, ByRef array5, ByRef count) 'this module reads a comma separated value file into some arrays Using MyReader As New Microsoft.VisualBasic.FileIO.TextFieldParser("N:\Visual Studio 2012\Hotel Info.csv")


Dim currentRow As String()


currentRow = MyReader.ReadFields() 'reads a line of the csv and stores it in the string variable called currentrow

count = count + 1 'keeps track of which line of the file was read

‘puts the values that are separated by the commas into the arrays array1(count) = currentRow(0).ToString array2(count) = Val(currentRow(1).ToString) 'val converts a string to a value array3(count) = currentRow(2).ToString array4(count) = Val(currentRow(3).ToString) 'val converts a string to a value array5(count) = currentRow(4).ToString


End While End Using End Sub

------------------------------------------------------------------------------------------

Private Sub display_arrays(ByRef array1, ByRef array2, ByRef array3, ByRef array4, ByRef array5, ByVal count) 'this module will display the contents of some arrays Dim index As Integer

For index = 1 To count ListBox1.Items.Add(array1(index)) ListBox2.Items.Add(array2(index)) ListBox3.Items.Add(array3(index)) ListBox4.Items.Add(array4(index)) ListBox5.Items.Add(array5(index)) Next End Sub------------------------------------------------------------------------------------------




John, Smith,5L,18/1/1998Susan, Brown,5M,20/3/1998Katie,Jones,5L,12/4/1998Kara,Green,5M,2/1/1998

End Class

Task 26: Improve the hotel data program so that it uses the “Find max” and “Linear search” procedures


Improve the hotel data program that reads data from a file and stores it in arrays so that it also displays the highest rating and the hotels that had that rating.

To test it you should change your Comma Separated Value file so that the Paisley Palm hotel has a rating of 5.

The output should look like this:-

Task 27: Read pupil data from a Comma Separated Value file and store it in arrays


Design and create a program that reads data from a file and stores it in arrays.

The data should include Forename, Surname, Register Class, Date of Birth.

You will need to create a Comma Separated Value file like this:-



Topic 9 – Using records

Task 28: Enter hotel data and store it in recordsProblem specification

Design and create a program that allows the user to enter data about hotels and stores it in records.

It should display output like this:-

The data will be stored in records in an array of records like this:-

Array

Index

hotelName hotelRating

hotelCity

hotelPricePerNight

hotelMealsIncluded

01 Glasgow

Caledonian5 Glasgow 59.99 Breakfast

2 Aberdeen Arms 3 Aberdeen 39.99 Breakfast3 Paisley Palm 4 Paisley 99.99 None4 Premier Inn 2 Glasgow 19.99 None5 Premier Inn 2 Carlisle 19.99 All meals


TOPIC 9 – USING RECORDS


1. initialise variables() in/out: allHotels, countOfHotels2. store_data_in_records() in/out: allHotels, countOfHotels3. display_records() in: allHotels, countOfHotels


Refine step 2 initialise variables() in/out: allHotels, countOfHotels

1.1 set countOfHotels to 51.2 start loop counter from 1 to countOfHotels1.3 set allHotels(loop counter).hotelName to “1.4 set allHotels(loop counter).hotelRating to 1.5 set allHotels(loop counter).hotelCity to “”1.6 set allHotels(loop counter).hotelPricePerNight to 1.7 set allHotels(loop counter).hotelMealsIncluded to “”1.8 end loop

Refine step 2 store_data_in_records() in/out: allHotels, countOfHotels2.1 start loop counter from to countOfHotels2.2 receive set allHotels(loop counter).hotelName from keyboard2.3 receive set allHotels(loop counter).hotelRating from keyboard2.4 receive set allHotels(loop counter).hotelCity from keyboard2.5 receive set allHotels(loop counter).hotelPricePerNight from keyboard2.6 receive set allHotels(loop counter).hotelMealsIncluded from keyboard2.7 end loop

Refine step 3: display_records() in: allHotels, countOfHotels

3.1 start loop counter from to countOfHotels3.2 send allHotels(loop counter).hotelName to display3.3 send allHotels(loop counter).hotelRating to display3.4 send allHotels(loop counter).hotelCity to display3.5 send allHotels(loop counter).hotelPricePerNight to display3.6 send allHotels(loop counter).hotelMealsIncluded to display3.7 end loop

Public Class Form1



Structure hotelRecord 'Declare the strucre of a record Dim hotelName As String Dim hotelRating As Integer Dim hotelCity As String Dim hotelPricePerNight As Single Dim hotelMealsIncluded As String

End Structure------------------------------------------------------------------------------------------ Private Sub cmdStart_Click(sender As Object, e As EventArgs) Handles cmdStart.Click ' Main program

Dim countOfHotels As Integer Dim allHotels(5) As hotelRecord

initialise(allHotels, countOfHotels) store_data_in_records(allHotels, countOfHotels) display_records(allHotels, countOfHotels)

End Sub------------------------------------------------------------------------------------------

Private Sub initialise(ByRef allHotels() As hotelRecord, ByRef countOfHotels As Integer) 'This module gives the records and countOfHotels initial values

Dim index As Integer countOfHotels = 5 'Set the number of hotels that are to be stored For index = 1 To countOfHotels allHotels(index).hotelName = "" allHotels(index).hotelRating = 0 allHotels(index).hotelCity = "" allHotels(index).hotelPricePerNight = 0 allHotels(index).hotelMealsIncluded = "" Next

End Sub------------------------------------------------------------------------------------------

Private Sub store_data_in_records(ByRef allHotels() As hotelRecord, ByVal countOfHotels As Integer) 'This module invites the user to enter data that is stored in an array of records


For index = 1 To countOfHotels

allHotels(index).hotelName = InputBox("Enter the name of hotel " & index) allHotels(index).hotelRating = InputBox("Enter the rating of hotel " & index) allHotels(index).hotelCity = InputBox("Enter the city of hotel " & index) allHotels(index).hotelPricePerNight = InputBox("Enter the price per night of hotel " & index) allHotels(index).hotelMealsIncluded = InputBox("Enter the meals included of hotel " & index)

Next



End Sub

Private Sub display_records(ByRef allHotels() As hotelRecord, ByVal countOfHotels As Integer) 'This module displays the data that is stored in an array of records


For index = 1 To countOfHotels ListBox1.Items.Add(allHotels(index).hotelName) ListBox2.Items.Add(allHotels(index).hotelRating) ListBox3.Items.Add(allHotels(index).hotelCity) ListBox4.Items.Add(allHotels(index).hotelPricePerNight) ListBox5.Items.Add(allHotels(index).hotelMealsIncluded) Next

End Sub


End Class

Load and run the program called Higher Task 28 Enter hotel data into records. Try changing it store a different number of records.



Task 29: Read hotel data from a Comma Separated Value file and store it in records


Improve the hotel records program so that the data is read from a file instead of the user entering it.

The output should still looks like this:-

The Comma Separated Value file looks like this:-




1. read_fie_into_records() in/out: allHotels, countOfHotels2. display_records() in: allHotels, countOfHotels


Refine step 1 read_fie_into_records() in/out: allHotels, countOfHotels

2.1 Using myReader to Open a file to read from it2.1 set countOfHotels to 02.1 loop while not at the end of the data2.1 try 2.1 set currentRow to a line in the file2.1 add 1 to countOfHotels2.1 set allHotels(countOfHotels).hotelName field to string 0 in the current line2.1 set allHotels(countOfHotels). hotelRating field to value 1 in the current

line2.1 set allHotels(countOfHotels). hotelCity field to string 2 in the current line2.1 set allHotels(countOfHotels). hotelPricePerNight field to value 3 in the

current line2.1 set allHotels(countOfHotels). hotelMealsIncluded field to string 4 in the

current line2.1 Catch file error2.1 display error message2.1 end try2.1 end loop2.1 End Using

Refine step 2 display_records() in: allHotels, countOfHotels

3.1 start loop counter from to countOfHotels3.1 send allHotels(loop counter).hotelName to display3.1 send allHotels(loop counter).hotelRating to display3.1 send allHotels(loop counter).hotelCity to display3.1 send allHotels(loop counter).hotelPricePerNight to display3.1 send allHotels(loop counter).hotelMealsIncluded to display3.1 end loop



Public Class Form1 Structure hotelRecord 'Declare the structure of a record about a hotel Dim hotelName As String Dim hotelRating As Integer Dim hotelCity As String Dim hotelPricePerNight As Single Dim hotelMealsIncluded As String End Structure------------------------------------------------------------------------------------------ Private Sub cmdStart_Click(sender As Object, e As EventArgs) Handles cmdStart.Click 'This module contains the main Program Dim allHotels(10) As hotelRecord Dim countOfHotels As Integer

read_file_into_records(allHotels, countOfHotels) display_records(allHotels, countOfHotels) End Sub------------------------------------------------------------------------------------------ Private Sub read_file_into_records(ByRef allHotels() As hotelRecord, ByRef countOfHotels As Integer) 'This module reads a Comma Separated Values file and stores the values in an array of records

'Open the file Using MyReader As New Microsoft.VisualBasic.FileIO.TextFieldParser("N:\Visual Studio 2012\Hotel Info.csv") 'Describe the type of file MyReader.TextFieldType = FileIO.FieldType.Delimited MyReader.SetDelimiters(",")

Dim currentRow As String() countOfHotels = 0 'while not at the end of the file a row of values is read and stored in a record While Not MyReader.EndOfData Try currentRow = MyReader.ReadFields() 'a row is read and stored in the string variable called currentRow

countOfHotels = countOfHotels + 1 'keep rack of which line of the file was read i.e. which record

'each value in the row is stored in a feild of the current record allHotels(countOfHotels).hotelName = currentRow(0).ToString allHotels(countOfHotels).hotelRating = Val(currentRow(1).ToString) allHotels(countOfHotels).hotelCity = currentRow(2).ToString allHotels(countOfHotels).hotelPricePerNight = Val(currentRow(3).ToString) allHotels(countOfHotels).hotelMealsIncluded = currentRow(4).ToString

'Display an error message if there is an error in the file



Catch ex As Microsoft.VisualBasic. FileIO.MalformedLineException MsgBox("Line " & ex.Message & "is not valid and will be skipped.") End Try End While End Using End Sub

Private Sub display_records(ByRef allHotels() As hotelRecord, ByVal countOfHotels As Integer) 'This module displays the data that is stored in the array of records Dim index As Integer

For index = 1 To countOfHotels ListBox1.Items.Add(allHotels(index).hotelName) ListBox2.Items.Add(allHotels(index).hotelRating) ListBox3.Items.Add(allHotels(index).hotelCity) ListBox4.Items.Add(allHotels(index).hotelPricePerNight) ListBox5.Items.Add(allHotels(index).hotelMealsIncluded) Next

End Sub------------------------------------------------------------------------------------------ Private Sub cmdExit_Click(sender As Object, e As EventArgs) Handles cmdExit.Click End End SubEnd Class------------------------------------------------------------------------------------------------------------------

Load and run the program called Higher Task 29 Read a file into records.

Add another line to the file and run the program again to check that all of the data is shown.



Topic 10 Writing a fileTask 30 – Read a file and write some of it to another file

Public Class Form1

Private Sub cmdStart_Click(sender As Object, e As EventArgs) Handles cmdStart.Click 'This module contains the main program





write(hotelName, hotelRating, countOfHotels) End Sub

Private Sub initialise(ByRef hotelName, ByRef hotelRating, ByRef hotelCity, ByRef hotelPricePerNight, ByRef hotelMealsIncluded, ByRef countOfHotels) 'This module will initialise the records so that the string fields are set to "" and the numeric fields, countOfHotels and are set to 0 Dim index As Integer


End Sub

Private Sub read_file_into_arrays(ByRef array1, ByRef array2, ByRef array3, ByRef array4, ByRef array5, ByRef count) 'this module reads a comma separated value file into some arrays Using MyReader As New Microsoft.VisualBasic.FileIO.TextFieldParser("N:\Visual Studio 2012\Hotel Info.csv")


Dim currentRow As String()




currentRow = MyReader.ReadFields() 'reads a line of the csv and stores it in the string variable called currentrow

count = count + 1 'keeps track of which line of the file was read

'puts the values that are separated by the commas into the arrays array1(count) = currentRow(0).ToString array2(count) = Val(currentRow(1).ToString) 'val converts a string to a value array3(count) = currentRow(2).ToString array4(count) = Val(currentRow(3).ToString) 'val converts a string to a value array5(count) = currentRow(4).ToString


End While End Using End Sub Private Sub write(ByRef array1, ByRef array2, ByRef count) 'this module reads a comma separated value file into some arrays

Dim file As System.IO.StreamWriter file = My.Computer.FileSystem.OpenTextFileWriter("N:\Visual Studio 2012\short hotel.csv", True)

For index = 1 To count If array2(index) > 2 Then file.WriteLine(array1(index) & "," & array2(index)) End If

Next

file.Close() file.Dispose()

End Sub

Private Sub display_arrays(ByRef array1, ByRef array2, ByRef array3, ByRef array4, ByRef array5, ByVal count) 'this module will display the contents of some arrays Dim index As Integer

For index = 1 To count ListBox1.Items.Add(array1(index)) ListBox2.Items.Add(array2(index)) ListBox3.Items.Add(array3(index)) ListBox4.Items.Add(array4(index)) ListBox5.Items.Add(array5(index)) Next End Sub

Private Sub cmdExit_Click(sender As Object, e As EventArgs) Handles cmdExit.Click End



End SubEnd Class

Load and run the program called Higher Task 30 - Read a hotel file and write some of it to another file.



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