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Arrays and Procedures

 

Arrays and Procedures

 

Introduction

Because an array is primarily treated as a variable, it shares the regular characteristics of other objects. For example, an array can be passed as argument and a function can return an array. The main difference is that an array by itself represents a group of items while a regular variable considers only its own value.

 

Practical LearningPractical Learning: Introducing Arrays and Procedures

  1. Start Notepad
  2. In the empty file, type the following:
     
    Public Class IceCream
        Public Const BasePrice As Double = 1.55
    
        Public Sub ProcessAnOrder()
            Dim dFlv As Integer, dCont As Integer, dIngrd As Integer
            Dim Scoops As Integer
            Dim PriceIngredient As Double, TotalPrice As Double
    
            Dim Flavor() As String = {"Vanilla", "Cream of Cocoa", "Organic Strawberry", _
                       "Butter Pecan", "Cherry Coke", "Chocolate Brownies"}
    
            Dim Container(3) As String
            Container(0) = "Cone"
            Container(1) = "Cup"
            Container(2) = "Bowl"
    
            Dim Ingredient() As String = {"No Ingredient", "Peanuts", "M & M", "Cookies"}
    
            Console.WriteLine("Ice Cream Vendor Machine")
    
            Do
                Try
                    Console.WriteLine("What type of flavor do you want?")
                    Console.WriteLine("1 - {0}", Flavor(0))
                    Console.WriteLine("2 - {0}", Flavor(1))
                    Console.WriteLine("3 - {0}", Flavor(2))
                    Console.WriteLine("4 - {0}", Flavor(3))
                    Console.WriteLine("5 - {0}", Flavor(4))
                    Console.WriteLine("6 - {0}", Flavor(5))
                    Console.Write("Your Choice? ")
                    dFlv = CInt(Console.ReadLine())
                Catch ex As InvalidCastException
                    Console.WriteLine("You must enter a valid number and no other character!")
                End Try
    
                If dFlv < 1 Or dFlv > 6 Then
                    Console.WriteLine("Invalid Choice - Try Again!" & vbCrLf)
                End If
            Loop While dFlv < 1 Or dFlv > 6
    
            Do
                Try
                    Console.WriteLine("What type of container do you want?")
                    Console.WriteLine("1 - {0}", Container(0))
                    Console.WriteLine("2 - {0}", Container(1))
                    Console.WriteLine("3 - {0}", Container(2))
                    Console.Write("Your Choice? ")
                    dCont = CInt(Console.ReadLine())
                Catch ex As InvalidCastException
                    Console.WriteLine("You must enter a valid number and no other character!")
                End Try
    
                If dCont < 1 Or dCont > 3 Then
                    Console.WriteLine("Invalid Choice - Try Again!")
                End If
            Loop While dCont < 1 Or dCont > 3
    
            Do
                Try
                    Console.WriteLine("Do you want an ingredient or not")
                    Console.WriteLine("1 - {0}", Ingredient(0))
                    Console.WriteLine("2 - {0}", Ingredient(1))
                    Console.WriteLine("3 - {0}", Ingredient(2))
                    Console.WriteLine("4 - {0}", Ingredient(3))
                    Console.Write("Your Choice? ")
                    dIngrd = CInt(Console.ReadLine())
                Catch ex As InvalidCastException
                    Console.WriteLine("You must enter a valid number and no other character!")
                End Try
    
                If dIngrd < 1 Or dIngrd > 4 Then
                    Console.WriteLine("Invalid Choice - Try Again!")
                End If
            Loop While dIngrd < 1 Or dIngrd > 4
    
            Do
                Try
                    Console.Write("How many scoops(1, 2, or 3)? ")
                    Scoops = CInt(Console.ReadLine())
                Catch ex As InvalidCastException
                    Console.WriteLine("You must enter a valid number and no other character!")
                End Try
    
                If Scoops < 1 Or Scoops > 3 Then
                    Console.WriteLine("Invalid Choice - Try Again!")
                End If
            Loop While Scoops < 1 Or Scoops > 3
    
            If dIngrd = 2 Or dIngrd = 3 Or dIngrd = 4 Then
                PriceIngredient = 0.65
            Else
                PriceIngredient = 0.0
            End If
    
            TotalPrice = (BasePrice * Scoops) + PriceIngredient
    
            DisplayReceipt(dFlv, dCont, dIngrd, Scoops, TotalPrice)
        End Sub
    
        Public Sub DisplayReceipt(ByVal Flv As Integer, ByVal Cont As Integer, _
                                  ByVal Ingrd As Integer, _
                                  ByVal spoons As Integer, ByVal TotalPrice As Double)
            Console.WriteLine(vbCrLf & "Ice Cream Order")
    
            Select Case Flv
                Case 2
                    Console.WriteLine("Flavor:      Cream of Cocoa")
                Case 3
                    Console.WriteLine("Flavor:      Organic Strawberry")
                Case 4
                    Console.WriteLine("Flavor:      Butter Pecan")
                Case 5
                    Console.WriteLine("Flavor:      Cherry Coke")
                Case 6
                    Console.WriteLine("Flavor:      Chocolate Brownies")
    
                Case Else
                    Console.WriteLine("Flavor:      Vavilla")
            End Select
    
            Select Case Cont
                Case 2
                    Console.WriteLine("Container:   Cup")
                Case 3
                    Console.WriteLine("Container:   Bowl")
                Case Else
                    Console.WriteLine("Container:   Cone")
            End Select
    
            Select Case Ingrd
                Case 2
                    Console.WriteLine("Ingredient:  Peanuts")
                Case 3
                    Console.WriteLine("Ingredient:  M & M")
                Case 4
                    Console.WriteLine("Ingredient:  Cookies")
                Case Else
                    Console.WriteLine("Ingredient:  None")
            End Select
    
            Console.WriteLine("Scoops:      {0}", spoons)
            Console.WriteLine("Total Price: {0:C}" & vbCrLf, TotalPrice)
        End Sub
    End Class
  3. Save the file in a new folder named IceCream2
  4. Save the file itself as IceCream.vb in the IceSream2 folder
  5. Start another instance of Notepad and type the following:
    Imports System
    
    Public Class Exercise
    
        Public Shared Sub main()
            Dim ic As IceCream = New IceCream
    
            ic.ProcessAnOrder()
        End Sub
    End Class
  6. Save the file as Exercise.vb in the IceCream2 folder
  7. Open the Command Prompt and switch to the IceCream2 folder
  8. Compile the exercise by typing vbc Exercise.vb and pressing Enter
  9. Execute the application by typing Exercise and pressing Enter. Here is an example of executing the program:
    Ice Cream Vendor Machine
    What type of flavor do you want?
    1 - Vanilla
    2 - Cream of Cocoa
    3 - Organic Strawberry
    4 - Butter Pecan
    5 - Cherry Coke
    6 - Chocolate Brownies
    Your Choice? 2
    What type of container do you want?
    1 - Cone
    2 - Cup
    3 - Bowl
    Your Choice? 1
    Do you want an ingredient or not
    1 - No Ingredient
    2 - Peanuts
    3 - M & M
    4 - Cookies
    Your Choice? 3
    How many scoops(1, 2, or 3)? 2
    
    Ice Cream Order
    Flavor:      Cream of Cocoa
    Container:   Cone
    Ingredient:  M & M
    Scoops:      2
    Total Price: $3.75
  10. Return to Notepad 
 

Passing a Member of an Array as Argument

Each member of an array is considered a sub-variable that is, a variable in its own right with a value. Based on this, you can pass a single member of an array as argument. In this case, you can pass the name of the array variable with the accompanying index to a procedure. Here is an example:

Imports System

Module Exercise
    Dim Names() As String = {"Hermine", "Gertrude", "Helene", "Paulette"}

    Private Sub ShowName(ByVal Name As String)
        Console.WriteLine("Name: {0}", Name)
    End Sub

    Public Sub main()
        ShowName(Names(2))

        Console.WriteLine()
    End Sub
End Module

This would produce:

Name: Helene

An Array Passed as Argument

The main purpose of using an array is to use various pseudo-variables grouped under one name. Still, an array is primarily a variable. As such, it can be passed to a procedure and it can be returned from one. Like a regular variable, an array can be passed as argument. To do this, in the parentheses of a procedure, provide the data type, the empty square brackets, and the name of the argument. Here is an example:

Imports System

Module Exercise
    Private Sub DisplayNumbers(ByVal args() As Double)

    End Sub

    Public Sub main()

    End Sub
End Module

When an array has been passed to a procedure, it can be used in the body of the procedure as any array can be, following the rules of array variables. For example, you can display its values. Because an array is derived from the Array class, an array passed as argument carries its number of members. This means that you don't have to pass an additional argument.

The simplest way you can use an array is to display the values of its members. This could be done as follows:

Imports System

Module Exercise
    Private Sub DisplayNumbers(ByVal args() As Double)
        For Each arg As Double In args
            Console.WriteLine("Number: {0}", arg)
        Next
    End Sub

    Public Sub main()

    End Sub
End Module

To call a procedure that takes an array as argument, simply type the name of the array in the parentheses of the called procedure. Here is an example:

Imports System

Module Exercise
    Private Sub DisplayNumbers(ByVal args() As Double)
        For Each arg As Double In args
            Console.WriteLine("Number: {0}", arg)
        Next
    End Sub

    Public Sub main()
        Dim number(4) As Double

        number(0) = 12.44
        number(1) = 525.38
        number(2) = 6.28
        number(3) = 2448.32
        number(4) = 632.04

        DisplayNumbers(number)
        Console.WriteLine()
    End Sub
End Module

This would produce:

Number: 12.44
Number: 525.38
Number: 6.28
Number: 2448.32
Number: 632.04

When an array is passed as argument to a procedure, the array is passed by reference. This means that, if the procedure makes any change to the array, the change would be kept when the procedure exits. This is illustrated in the following program:

Imports System

Module Exercise
    Private Sub DisplayNumber(ByVal args() As Double)
        For Each arg As Double In args
            Console.WriteLine("Number: {0}", arg)
        Next

        args(0) = -888.64
        args(1) = 24.57
        args(2) = 60450.24
        args(3) = -6.4
        args(4) = 900.002
    End Sub

    Public Sub main()
        Dim Numbers(4) As Double

        numbers(0) = 12.44
        numbers(1) = 525.38
        numbers(2) = 6.28
        Numbers(3) = 2448.32
        Numbers(4) = 632.04

        Console.WriteLine("=-= First Call =-=")
        For Each nbr As Double In Numbers
            Console.WriteLine("Number: {0}", nbr)
        Next
        Console.WriteLine()

        Console.WriteLine("=-= External Call =-=")
        DisplayNumber(Numbers)
        Console.WriteLine()

        Console.WriteLine("=-= Second Call =-=")
        For Each nbr As Double In Numbers
            Console.WriteLine("Number: {0}", nbr)
        Next
        Console.WriteLine()
    End Sub
End Module

This would produce:

=-= First Call =-=
Number: 12.44
Number: 525.38
Number: 6.28
Number: 2448.32
Number: 632.04

 =-= External Call =-=
Number: 12.44
Number: 525.38
Number: 6.28
Number: 2448.32
Number: 632.04

 =-= Second Call =-=
Number: -888.64
Number: 24.57
Number: 60450.24
Number: -6.4
Number: 900.002

In the Main function, the array is primarily initialized and its values are displayed to the screen. The array is then passed to an external procedure. That procedure receives the array ByVal. It displays the values of the array as they were passed it. Before exiting, the procedure modifies the array and closes. Back in Main(), the array is displayed without receiving any modification. But the values of the array appear different. This is because the array was modified by the called procedure. This illustrates that an array is passed by reference even if you don't use the ByRef keyword on the argument. You can use this characteristic to initialize an array from a procedure. Here is an example:

Imports System

Module Exercise
    Private Sub InitializeNumbers(ByVal args() As Double)
        args(0) = -888.64
        args(1) = 24.57
        args(2) = 60450.24
        args(3) = -6.4
        args(4) = 900.002
    End Sub

    Private Sub DisplayNumbers(ByVal nbrs() As Double)
        For Each nbr As Double In nbrs
            Console.WriteLine("Number: {0}", nbr)
        Next
    End Sub

    Public Sub main()
        Dim Numbers(4) As Double

        InitializeNumbers(Numbers)
        DisplayNumbers(Numbers)
        Console.WriteLine()
    End Sub
End Module

Notice that the InitializeList() procedure receives an un-initialized array but returns it with new values.

Because an array is passed by reference, if you want to explicitly indicate this, when passing an array, you can accompany it with the ByRef keyword. Here is an example:

Imports System

Module Exercise
    Private Sub InitializeNumbers(ByRef args() As Double)
        args(0) = 542.28
        args(1) = 64.96
        args(2) = 4750.25
        args(3) = 28.44
        args(4) = 18500.45
    End Sub

    Private Sub DisplayNumbers(ByVal nbrs() As Double)
        For Each nbr As Double In nbrs
            Console.WriteLine("Number: {0}", nbr)
        Next
    End Sub

    Public Sub main()
        Dim Numbers(4) As Double

        InitializeNumbers(Numbers)
        DisplayNumbers(Numbers)
        Console.WriteLine()
    End Sub
End Module

This would produce:

Number: 542.28
Number: 64.96
Number: 4750.25
Number: 28.44
Number: 18500.45
 

Practical LearningPractical Learning: Passing an Array as Argument

  1. To use examples of passing arrays to procedures, change the Order.vb file as follows:
     
    Public Class IceCream
        Public Const BasePrice As Double = 1.55
    
        Private Sub CreateFlavors(ByVal Flavors() As String)
            Flavors(0) = "Vanilla"
            Flavors(1) = "Cream of Cocoa"
            Flavors(2) = "Organic Strawberry"
            Flavors(3) = "Butter Pecan"
            Flavors(4) = "Cherry Coke"
            Flavors(5) = "Chocolate Brownies"
        End Sub
    
        Private Sub CreateIngredients(ByVal Ingredients() As String)
            Ingredients(0) = "No Ingredient"
            Ingredients(1) = "Peanuts"
            Ingredients(2) = "M & M"
            Ingredients(3) = "Cookies"
        End Sub
    
        Private Function ChooseContainer(ByVal Containers() As String) As Integer
            Dim choice As Integer = 1
    
            Do
                Try
                    Console.WriteLine("What type of container do you want?")
                    For i As Integer = 0 To 2
                        Console.WriteLine("{0} - {1}", i + 1, Containers(i))
                    Next
                    Console.Write("Your Choice? ")
                    choice = CInt(Console.ReadLine())
                Catch ex As InvalidCastException
                    Console.WriteLine("You must enter a valid number and no other character!")
                End Try
    
                If choice < 1 Or choice > 3 Then
                    Console.WriteLine("Invalid Choice - Try Again!")
                End If
            Loop While choice < 1 Or choice > 3
    
            Return choice
        End Function
    
        Private Function RequestFlavor(ByVal Flavors() As String) As Integer
            Dim choice As Integer = 1
    
            Do
                Try
                    Console.WriteLine("What type of flavor do you want?")
                    For i As Integer = 0 To 5
                        Console.WriteLine("{0} - {1}", i + 1, Flavors(i))
                    Next
                    Console.Write("Your Choice? ")
                    choice = CInt(Console.ReadLine())
                Catch ex As InvalidCastException
                    Console.WriteLine("You must enter a valid number and no other character!")
                End Try
    
                If choice < 1 Or choice > 6 Then
                    Console.WriteLine("Invalid Choice - Try Again!" & vbcrlf)
                End If
            Loop While choice < 1 Or choice > 6
    
            Return choice
        End Function
    
        Private Function RequestIngredient(ByVal Ingredients() As String) As Integer
            Dim choice As Integer = 1
    
            Do
                Try
                    Console.WriteLine("Do you want an ingredient or not")
                    For i As Integer = 0 To 3
                        Console.WriteLine("{0} - {1}", i + 1, Ingredients(i))
                    Next
                    Console.Write("Your Choice? ")
                    choice = CInt(Console.ReadLine())
                Catch ex As InvalidCastException
                    Console.WriteLine("You must enter a valid number and no other character!")
                End Try
    
                If choice < 1 Or choice > 4 Then
                    Console.WriteLine("Invalid Choice - Try Again!")
                End If
            Loop While choice < 1 Or choice > 4
    
            Return choice
        End Function
    
        Private Function GetTheNumberOfScoops() As Integer
            Dim number As Integer = 1
    
            Do
                Try
                    Console.Write("How many scoops(1, 2, or 3)? ")
                    number = CInt(Console.ReadLine())
                Catch ex As InvalidCastException
                    Console.WriteLine("You must enter a valid number and no other character!")
                End Try
    
                If number < 1 Or number > 3 Then
                    Console.WriteLine("Invalid Choice - Try Again!")
                End If
            Loop While number < 1 Or number > 3
    
            Return number
        End Function
    
        Public Sub ProcessAnOrder()
            Dim dFlv As Integer, dCont As Integer, dIngrd As Integer
            Dim Scoops As Integer
            Dim PriceIngredient As Double, PriceScoop As Double, TotalPrice As Double
    
            Dim Flavors(6) As String
            Dim Containers(3) As String
            Dim Ingredients(4) As String
    
            Containers(0) = "Cone"
            Containers(1) = "Cup"
            Containers(2) = "Bowl"
    
            CreateFlavors(Flavors)
            CreateIngredients(Ingredients)
    
            dFlv = RequestFlavor(Flavors)
            dCont = ChooseContainer(Containers)
            dIngrd = RequestIngredient(Ingredients)
            Scoops = GetTheNumberOfScoops()
    
            If dIngrd = 2 Or dIngrd = 3 Or dIngrd = 4 Then
                PriceIngredient = 0.5
            Else
                PriceIngredient = 0.0
            End If
    
            If Scoops = 1 Then
                PriceScoop = 0.65
            ElseIf Scoops = 2 Then
                PriceScoop = 1.05
            Else
                PriceScoop = 1.55
            End If
    
            Console.WriteLine("Ice Cream Vendor Machine")
    
            TotalPrice = BasePrice + PriceScoop + PriceIngredient
    
            DisplayReceipt(Flavors(dFlv - 1), Containers(dCont - 1), _
                  Ingredients(dIngrd - 1), Scoops, TotalPrice)
        End Sub
    
        Public Sub DisplayReceipt(ByVal Flv As String, ByVal Cont As String, _
                                  ByVal Ingrd As String, _
                                  ByVal spoons As Integer, ByVal TotalPrice As Double)
            Console.WriteLine(vbCrLf & "Ice Cream Order")
            Console.WriteLine("Flavor:      {0}", Flv)
            Console.WriteLine("Container:   {0}", Cont)
            Console.WriteLine("Ingredient:  {0}", Ingrd)
            Console.WriteLine("Scoops:      {0}", spoons)
            Console.WriteLine("Total Price: {0:C}" & vbCrLf, TotalPrice)
        End Sub
    
    End Class
  2. Save, compile, and test the program. Here is an example of running the program:
     
    What type of flavor do you want?
    1 - Vanilla
    2 - Cream of Cocoa
    3 - Organic Strawberry
    4 - Butter Pecan
    5 - Cherry Coke
    6 - Chocolate Brownies
    Your Choice? 0
    Invalid Choice - Try Again!
    
    What type of flavor do you want?
    1 - Vanilla
    2 - Cream of Cocoa
    3 - Organic Strawberry
    4 - Butter Pecan
    5 - Cherry Coke
    6 - Chocolate Brownies
    Your Choice? 7
    Invalid Choice - Try Again!
    
    What type of flavor do you want?
    1 - Vanilla
    2 - Cream of Cocoa
    3 - Organic Strawberry
    4 - Butter Pecan
    5 - Cherry Coke
    6 - Chocolate Brownies
    Your Choice? 5
    What type of container do you want?
    1 - Cone
    2 - Cup
    3 - Bowl
    Your Choice? 0
    Invalid Choice - Try Again!
    What type of container do you want?
    1 - Cone
    2 - Cup
    3 - Bowl
    Your Choice? 3
    Do you want an ingredient or not
    1 - No Ingredient
    2 - Peanuts
    3 - M & M
    4 - Cookies
    Your Choice? 0
    Invalid Choice - Try Again!
    Do you want an ingredient or not
    1 - No Ingredient
    2 - Peanuts
    3 - M & M
    4 - Cookies
    Your Choice? 8
    Invalid Choice - Try Again!
    Do you want an ingredient or not
    1 - No Ingredient
    2 - Peanuts
    3 - M & M
    4 - Cookies
    Your Choice? 4
    How many scoops(1, 2, or 3)? 2
    Ice Cream Vendor Machine
    
    Ice Cream Order
    Flavor: Cherry Coke
    Container: Bowl
    Ingredient: Cookies
    Scoops: 2
    Total Price: $3.10
  3. Return to Notepad

A Function that Returns an Array

In the previous section, we saw that a (sub) procedure could return an array because if it modifies an array it receives as argument, the array keeps the new value. Still, you can use a function to formally return an array. When declaring or defining the function, you must specify its data type.

To create a function that returns an array, on the left of the function's name, provide the type of value that the returned array  will be made of, followed by empty parentheses. Here is an example:

Private Function InitializeValues() As Double()
        
End Function

Remember that a function must always return an appropriate value depending on how it was declared. In this case, if it was specified as returning an array, then make sure it returns an array and not a regular variable. One way you can do this is to declare and possibly initialize a local array variable. After using the local array, you return only its name (without the parentheses). Here is an example:

Private Function InitializeValues() As Double()
        Dim Values(4) As Double

        Values(0) = 542.28
        Values(1) = 64.96
        Values(2) = 4750.25
        Values(3) = 28.44
        Values(4) = 18500.45
        InitializeValues = Values
End Function

When a function returns an array, that function can be assigned to an array declared locally when you want to use it. Remember to initialize a variable with such a function only if the variable is an array. If you initialize an array variable with a procedure that doesn't return an array, you would receive an error.

Here is an example:

Imports System

Module Exercise
    Private Function InitializeValues() As Double()
        Dim Values(4) As Double

        Values(0) = 542.28
        Values(1) = 64.96
        Values(2) = 4750.25
        Values(3) = 28.44
        Values(4) = 18500.45
        InitializeValues = Values
    End Function

    Private Sub DisplayNumbers(ByVal nbrs() As Double)
        For Each nbr As Double In nbrs
            Console.WriteLine("Number: {0}", nbr)
        Next
    End Sub

    Public Sub main()
        Dim Numbers(4) As Double

        Numbers = InitializeValues()
        DisplayNumbers(Numbers)
        Console.WriteLine()
    End Sub
End Module

This would produce:

Number: 542.28
Number: 64.96
Number: 4750.25
Number: 28.44
Number: 18500.45

Practical LearningPractical Learning: Returning an Array From a Procedure

  1. To apply an example of returning an array from a function, and to complete this exercise change the Order.vb file as follows:
     
    Public Class IceCream
        Public Const BasePrice As Double = 1.55
    
        Dim ChoiceFlavor As Integer
        Dim ChoiceContainer As Integer
        Dim ChoiceIngredient As Integer
        Dim Scoops As Integer
        Dim TotalPrice As Double
    
        Private Function PrepareFlavors() As String()
            Dim Flavors(10) As String
    
            Flavors(0) = "Vanilla"
            Flavors(1) = "Cream of Cocoa"
            Flavors(2) = "Chocolate Chip"
            Flavors(3) = "Organic Strawberry"
            Flavors(4) = "Butter Pecan"
            Flavors(5) = "Cherry Coke"
            Flavors(6) = "Chocolate Brownies"
            Flavors(7) = "Caramel Au Lait"
            Flavors(8) = "Chunky Butter"
            Flavors(9) = "Chocolate Cookie"
    
            Return Flavors
        End Function
    
        Private Sub CreateIngredients(ByRef Ingredients() As String)
            Ingredients(0) = "No Ingredient"
            Ingredients(1) = "Peanuts"
            Ingredients(2) = "M & M"
            Ingredients(3) = "Cookies"
        End Sub
    
        Private Sub ChooseContainer(ByRef Containers() As String)
            Containers(0) = "Cone"
            Containers(1) = "Cup"
            Containers(2) = "Bowl"
    
            Do
                Try
                    Console.WriteLine("What type of container do you want?")
                    For i As Integer = 0 To 2 Step 1
                        Console.WriteLine("{0} - {1}", i + 1, Containers(i))
                    Next
                    Console.Write("Your Choice? ")
                    ChoiceContainer = CInt(Console.ReadLine())
    
                Catch ex As InvalidCastException
                    Console.WriteLine("You must enter a valid number and no other character!")
                End Try
    
                If ChoiceContainer < 1 Or ChoiceContainer > 3 Then
                    Console.WriteLine("Invalid Choice - Try Again!")
                End If
            Loop While ChoiceContainer < 1 Or ChoiceContainer > 3
        End Sub
    
        Private Sub RequestFlavor(ByRef Flavors() As String)
            Flavors = PrepareFlavors()
    
            Do
                Try
                    Console.WriteLine("What type of flavor do you want?")
                    For i As Integer = 0 To 9 Step 1
                        Console.WriteLine("{0} - {1}", i + 1, Flavors(i))
                    Next
                    Console.Write("Your Choice? ")
                    ChoiceFlavor = CInt(Console.ReadLine())
    
                Catch exc As InvalidCastException
                    Console.WriteLine("You must enter a valid number and no other character!")
                End Try
    
                If ChoiceFlavor < 1 Or ChoiceFlavor > 10 Then
                    Console.WriteLine("Invalid Choice - Try Again!" & vbCrLf)
                End If
            Loop While ChoiceFlavor < 1 Or ChoiceFlavor > 10
        End Sub
    
        Private Sub ProcessIngredients(ByRef Ingredients() As String)
            CreateIngredients(Ingredients)
    
            Do
                Try
                    Console.WriteLine("Do you want an ingredient or not")
                    For i As Integer = 0 To 3 Step 1
                        Console.WriteLine("{0} - {1}", i + 1, Ingredients(i))
                    Next
                    Console.Write("Your Choice? ")
                    ChoiceIngredient = CInt(Console.ReadLine())
                Catch ex As InvalidCastException
                    Console.WriteLine("You must enter a valid number and no other character!")
                End Try
    
                If ChoiceIngredient < 1 Or ChoiceIngredient > 4 Then
                    Console.WriteLine("Invalid Choice - Try Again!")
                End If
            Loop While ChoiceIngredient < 1 Or ChoiceIngredient > 4
        End Sub
    
        Private Sub GetTheNumberOfScoops()
            Do
                Try
                    Console.Write("How many scoops(1, 2, or 3)? ")
                    Scoops = CInt(Console.ReadLine())
                Catch ex As InvalidCastException
                    Console.WriteLine("You must enter a valid number and no other character!")
                End Try
    
                If Scoops < 1 Or Scoops > 3 Then
                    Console.WriteLine("Invalid Choice - Try Again!")
                End If
            Loop While Scoops < 1 Or Scoops > 3
        End Sub
    
        Public Sub ProcessAnOrder()
            Dim PriceIngredient As Double, PriceScoop As Double
    
            Dim Flavor(10) As String
            Dim Container(3) As String
            Dim Ingredient(4) As String
    
            RequestFlavor(Flavor)
            ChooseContainer(Container)
            ProcessIngredients(Ingredient)
            GetTheNumberOfScoops()
    
            If ChoiceIngredient = 2 Or ChoiceIngredient = 3 Or ChoiceIngredient = 4 Then
                PriceIngredient = 0.5
            Else
                PriceIngredient = 0.0
            End If
    
            If Scoops = 1 Then
                PriceScoop = 0.65
            ElseIf Scoops = 2 Then
                PriceScoop = 1.05
            Else
                PriceScoop = 1.55
            End If
    
            Console.WriteLine("Ice Cream Vendor Machine")
    
            TotalPrice = BasePrice + PriceScoop + PriceIngredient
    
            DisplayReceipt(Flavor, Container, Ingredient)
        End Sub
    
        Public Sub DisplayReceipt(ByRef Flv() As String, ByRef Cont() As String, _
                                  ByRef Ingrd() As String)
    
            Console.WriteLine(vbCrLf & "Ice Cream Order")
            Console.WriteLine("Flavor:      {0}", Flv(ChoiceFlavor))
            Console.WriteLine("Container:   {0}", Cont(ChoiceContainer))
            Console.WriteLine("Ingredient:  {0}", Ingrd(ChoiceIngredient))
            Console.WriteLine("Scoops:      {0}", Scoops)
            Console.WriteLine("Total Price: {0:C}" & vbCrLf, TotalPrice)
        End Sub
    
    End Class
  2. Save, compile, and test the program. Then return to Notepad
 

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