1. VB.Net Programming Console Application
Walkthrough
Example : 2 Dimensional Array
PhoneList

2. Narrative Memory Code Screen 1 2 1 2 3 4 5 PhoneList Fail
This statement declares the Array in memory.
The Array is called PhoneList
It has 5 rows and 2 columns.*
* There is also a row 0 and a column 0 –but we shall ignore those in this example.
PhoneList 1 2 1 2
Code 3
Sub Main()
Dim PhoneList(5, 2) As String
'Fill the Array with data
PhoneList(1, 1) = "Jim"
PhoneList(1, 2) = " "
PhoneList(2, 1) = "Ann"
PhoneList(2, 2) = " "
PhoneList(3, 1) = “Raf"
PhoneList(3, 2) = " "
PhoneList(4, 1) = "Yen"
PhoneList(4, 2) = " "
PhoneList(5, 1) = "Will"
PhoneList(5, 2) = " " 4 5
Fail
Screen

3. Narrative Memory Code Screen 1 2 1 2 3 4 5 PhoneList Fail
This line is a comment. It simply states what the next section of code will perform.
PhoneList 1 2 1 2
Code 3
Sub Main()
Dim PhoneList(5, 2) As String
'Fill the Array with data
PhoneList(1, 1) = "Jim"
PhoneList(1, 2) = " "
PhoneList(2, 1) = "Ann"
PhoneList(2, 2) = " "
PhoneList(3, 1) = “Raf"
PhoneList(3, 2) = " "
PhoneList(4, 1) = "Yen"
PhoneList(4, 2) = " "
PhoneList(5, 1) = "Will"
PhoneList(5, 2) = " " 4 5
Fail
Screen

4. Narrative Memory Code Screen 1 2 1 Jim 2 3 4 5 PhoneList Fail
“Jim” is placed into the array PhoneList.
It is placed at row 1 column 1.
PhoneList 1 2 1
Jim 2
Code 3
Sub Main()
Dim PhoneList(5, 2) As String
'Fill the Array with data
PhoneList(1, 1) = "Jim"
PhoneList(1, 2) = " "
PhoneList(2, 1) = "Ann"
PhoneList(2, 2) = " "
PhoneList(3, 1) = “Raf"
PhoneList(3, 2) = " "
PhoneList(4, 1) = "Yen"
PhoneList(4, 2) = " "
PhoneList(5, 1) = "Will"
PhoneList(5, 2) = " " 4 5
Fail
Screen

5. Narrative Memory Code Screen 1 2 1 Jim 355 5671 2 3 4 5 PhoneList Fail
“ ” is placed into the array PhoneList.
It is placed at row 1 column 2.
PhoneList 1 2 1
Jim 2
Code 3
Sub Main()
Dim PhoneList(5, 2) As String
'Fill the Array with data
PhoneList(1, 1) = "Jim"
PhoneList(1, 2) = " "
PhoneList(2, 1) = "Ann"
PhoneList(2, 2) = " "
PhoneList(3, 1) = “Raf"
PhoneList(3, 2) = " "
PhoneList(4, 1) = "Yen"
PhoneList(4, 2) = " "
PhoneList(5, 1) = "Will"
PhoneList(5, 2) = " " 4 5
Fail
Screen

6. Narrative Memory Code Screen 1 2 1 Jim 355 5671 2 Ann 3 4 5 PhoneList
“Ann” is placed into the array PhoneList.
It is placed at row 2 column 1.
PhoneList 1 2 1
Jim 2
Ann
Code 3
Sub Main()
Dim PhoneList(5, 2) As String
'Fill the Array with data
PhoneList(1, 1) = "Jim"
PhoneList(1, 2) = " "
PhoneList(2, 1) = "Ann"
PhoneList(2, 2) = " "
PhoneList(3, 1) = “Raf"
PhoneList(3, 2) = " "
PhoneList(4, 1) = "Yen"
PhoneList(4, 2) = " "
PhoneList(5, 1) = "Will"
PhoneList(5, 2) = " " 4 5
Fail
Screen

7. Narrative Memory Code Screen 1 2 1 Jim 355 5671 2 Ann 257 5073 3 4 5
“ ” is placed into the array PhoneList.
It is placed at row 2 column 2.
PhoneList 1 2 1
Jim 2
Ann
Code 3
Sub Main()
Dim PhoneList(5, 2) As String
'Fill the Array with data
PhoneList(1, 1) = "Jim"
PhoneList(1, 2) = " "
PhoneList(2, 1) = "Ann"
PhoneList(2, 2) = " "
PhoneList(3, 1) = “Raf"
PhoneList(3, 2) = " "
PhoneList(4, 1) = "Yen"
PhoneList(4, 2) = " "
PhoneList(5, 1) = "Will"
PhoneList(5, 2) = " " 4 5
Fail
Screen

8. Narrative Memory Code Screen 1 2 1 Jim 355 5671 2 Ann 257 5073 3 Raf
These statements continue to fill the PhoneList array with Names & Phone Numbers.
Note
The first number in the brackets states the row
The second number states the column.
PhoneList 1 2 1
Jim 2
Ann 3
Raf
Code
Sub Main()
Dim PhoneList(5, 2) As String
'Fill the Array with data
PhoneList(1, 1) = "Jim"
PhoneList(1, 2) = " "
PhoneList(2, 1) = "Ann"
PhoneList(2, 2) = " "
PhoneList(3, 1) = “Raf"
PhoneList(3, 2) = " "
PhoneList(4, 1) = "Yen"
PhoneList(4, 2) = " "
PhoneList(5, 1) = "Will"
PhoneList(5, 2) = " " 4
Yen 5
Will
Fail
Screen

9. Narrative Memory Code Screen 1 2 1 Jim 355 5671 2 Ann 257 5073 3 Raf
This next example will search for a name within the PhoneList & display the phone number.
However, if the name is not found in the PhoneList a message “Name not in list” is displayed.
PhoneList 1 2 1
Jim 2
Ann 3
Raf
Code
'Searching the array
Dim SearchName As String
Dim Found As Boolean
Dim RowCount As Integer
Console.Clear()
Console.Write("Enter Name.....:")
SearchName = Console.ReadLine( )
Found = False
RowCount = 0
While Found = False And RowCount < 5
RowCount = RowCount + 1
If PhoneList(RowCount, 1) = SearchName Then
Found = True
End If
End While
If Found = True Then
Console.WriteLine("Phone Number...:{0}", _
PhoneList(RowCount, 2))
Else
Console.WriteLine("Name not in list")
Console.ReadKey()
End Sub 4
Yen 5
Will
Fail
Screen

10. Narrative Memory Code Screen 1 2 1 Jim 355 5671 2 Ann 257 5073 3 Raf
This line is a comment and simply states what the next section of code will do.
PhoneList 1 2 1
Jim 2
Ann 3
Raf
Code
'Searching the array
Dim SearchName As String
Dim Found As Boolean
Dim RowCount As Integer
Console.Clear()
Console.Write("Enter Name.....:")
SearchName = Console.ReadLine( )
Found = False
RowCount = 0
While Found = False And RowCount < 5
RowCount = RowCount + 1
If PhoneList(RowCount, 1) = SearchName Then
Found = True
End If
End While
If Found = True Then
Console.WriteLine("Phone Number...:{0}", _
PhoneList(RowCount, 2))
Else
Console.WriteLine("Name not in list")
Console.ReadKey()
End Sub 4
Yen 5
Will
Fail
Screen

11. Narrative Memory Code Screen 1 2 1 Jim 355 5671 2 Ann 257 5073 3 Raf
These DIM statements set up memory to store:
SearchName -the name to search the list for.
Found – boolean (True/False value) initially set to FALSE but set to TRUE if a match is found for the SearchName.
RowCount – to count through the rows in the array.
PhoneList 1 2
SearchName 1
Jim 2
Ann
Found 3
Raf
Code
'Searching the array
Dim SearchName As String
Dim Found As Boolean
Dim RowCount As Integer
Console.Clear()
Console.Write("Enter Name.....:")
SearchName = Console.ReadLine( )
Found = False
RowCount = 0
While Found = False And RowCount < 5
RowCount = RowCount + 1
If PhoneList(RowCount, 1) = SearchName Then
Found = True
End If
End While
If Found = True Then
Console.WriteLine("Phone Number...:{0}", _
PhoneList(RowCount, 2))
Else
Console.WriteLine("Name not in list")
Console.ReadKey()
End Sub 4
Yen
RowCount 5
Will
Fail
Screen

12. Narrative Memory Ann Code Screen Enter Name…: Ann 1 2 1 Jim 355 5671 2
The console screen is cleared.
The user is prompted to enter the name to search for.
The user types the name ( Ann in this example)
and it is stored in memory as SearchName.
PhoneList 1 2
SearchName
Ann 1
Jim 2
Ann
Found 3
Raf
Code
'Searching the array
Dim SearchName As String
Dim Found As Boolean
Dim RowCount As Integer
Console.Clear()
Console.Write("Enter Name.....:")
SearchName = Console.ReadLine( )
Found = False
RowCount = 0
While Found = False And RowCount < 5
RowCount = RowCount + 1
If PhoneList(RowCount, 1) = SearchName Then
Found = True
End If
End While
If Found = True Then
Console.WriteLine("Phone Number...:{0}", _
PhoneList(RowCount, 2))
Else
Console.WriteLine("Name not in list")
Console.ReadKey()
End Sub 4
Yen
RowCount 5
Will
Fail
Screen
Enter Name…: Ann

13. Narrative Memory Ann Code False Screen Enter Name…: Ann 1 2 1 Jim
Found is set to False – note it is set to true if a match for SearchName is found in the PhoneList.
RowCount is set to 0 – This is used to count through each row of the PhoneList.
PhoneList 1 2
SearchName
Ann 1
Jim 2
Ann
Found
False 3
Raf
Code
'Searching the array
Dim SearchName As String
Dim Found As Boolean
Dim RowCount As Integer
Console.Clear()
Console.Write("Enter Name.....:")
SearchName = Console.ReadLine( )
Found = False
RowCount = 0
While Found = False And RowCount < 5
RowCount = RowCount + 1
If PhoneList(RowCount, 1) = SearchName Then
Found = True
End If
End While
If Found = True Then
Console.WriteLine("Phone Number...:{0}", _
PhoneList(RowCount, 2))
Else
Console.WriteLine("Name not in list")
Console.ReadKey()
End Sub 4
Yen
RowCount 5
Will
Fail
Screen
Enter Name…: Ann

14. Narrative Memory Ann Code False Screen Enter Name…: Ann 1 2 1 Jim
This while loop will continue while Found = False (I.e. we have not found what we are looking for)
AND
RowCount is less than 5 (I.e. we have not reached the end of the PhoneList.
PhoneList 1 2
SearchName
Ann 1
Jim 2
Ann
Found
False 3
Raf
Code
'Searching the array
Dim SearchName As String
Dim Found As Boolean
Dim RowCount As Integer
Console.Clear()
Console.Write("Enter Name.....:")
SearchName = Console.ReadLine( )
Found = False
RowCount = 0
While Found = False And RowCount < 5
RowCount = RowCount + 1
If PhoneList(RowCount, 1) = SearchName Then
Found = True
End If
End While
If Found = True Then
Console.WriteLine("Phone Number...:{0}", _
PhoneList(RowCount, 2))
Else
Console.WriteLine("Name not in list")
Console.ReadKey()
End Sub 4
Yen
RowCount 5
Will
Fail
Screen
Enter Name…: Ann

15. Narrative Memory Ann Code False 1 Screen Enter Name…: Ann 1 2 1 Jim
This statement increments the RowCount so that we move through each row of the PhoneList
( that’s one row each time we go through this loop)
RowCount is incremented fro 0 to 1
PhoneList 1 2
SearchName
Ann 1
Jim 2
Ann
Found
False 3
Raf
Code
'Searching the array
Dim SearchName As String
Dim Found As Boolean
Dim RowCount As Integer
Console.Clear()
Console.Write("Enter Name.....:")
SearchName = Console.ReadLine( )
Found = False
RowCount = 0
While Found = False And RowCount < 5
RowCount = RowCount + 1
If PhoneList(RowCount, 1) = SearchName Then
Found = True
End If
End While
If Found = True Then
Console.WriteLine("Phone Number...:{0}", _
PhoneList(RowCount, 2))
Else
Console.WriteLine("Name not in list")
Console.ReadKey()
End Sub 4
Yen
RowCount 5
Will 1
Fail
Screen
Enter Name…: Ann

16. Narrative Memory Ann Code False 1 Screen Enter Name…: Ann 1 2 1 Jim
This IF statement compares the SearchName with column one of the PhoneList where row is RowCount. That is row 1 column 1 = Jim.
If they match then Found is set to True
If they do not match Found remains False.
Ann does not match Jim
PhoneList 1 2
SearchName
Ann 1
Jim 2
Ann
Found
False 3
Raf
Code
'Searching the array
Dim SearchName As String
Dim Found As Boolean
Dim RowCount As Integer
Console.Clear()
Console.Write("Enter Name.....:")
SearchName = Console.ReadLine( )
Found = False
RowCount = 0
While Found = False And RowCount < 5
RowCount = RowCount + 1
If PhoneList(RowCount, 1) = SearchName Then
Found = True
End If
End While
If Found = True Then
Console.WriteLine("Phone Number...:{0}", _
PhoneList(RowCount, 2))
Else
Console.WriteLine("Name not in list")
Console.ReadKey()
End Sub 4
Yen
RowCount 5
Will 1
Fail
Screen
Enter Name…: Ann

17. Narrative Memory Ann Code False 1 Screen Enter Name…: Ann 1 2 1 Jim
The variables are tested again to see if the while loop should run through again.
Found is still = False AND
RowCount is still less than 5
So the loop runs through once more.
PhoneList 1 2
SearchName
Ann 1
Jim 2
Ann
Found
False 3
Raf
Code
'Searching the array
Dim SearchName As String
Dim Found As Boolean
Dim RowCount As Integer
Console.Clear()
Console.Write("Enter Name.....:")
SearchName = Console.ReadLine( )
Found = False
RowCount = 0
While Found = False And RowCount < 5
RowCount = RowCount + 1
If PhoneList(RowCount, 1) = SearchName Then
Found = True
End If
End While
If Found = True Then
Console.WriteLine("Phone Number...:{0}", _
PhoneList(RowCount, 2))
Else
Console.WriteLine("Name not in list")
Console.ReadKey()
End Sub 4
Yen
RowCount 5
Will 1
Fail
Screen
Enter Name…: Ann

18. Narrative Memory Ann Code False 2 Screen Enter Name…: Ann 1 2 1 Jim
This statement increments the RowCount so that we move through each row of the PhoneList
( that’s one row each time we go through this loop)
RowCount is incremented from 1 to 2
PhoneList 1 2
SearchName
Ann 1
Jim 2
Ann
Found
False 3
Raf
Code
'Searching the array
Dim SearchName As String
Dim Found As Boolean
Dim RowCount As Integer
Console.Clear()
Console.Write("Enter Name.....:")
SearchName = Console.ReadLine( )
Found = False
RowCount = 0
While Found = False And RowCount < 5
RowCount = RowCount + 1
If PhoneList(RowCount, 1) = SearchName Then
Found = True
End If
End While
If Found = True Then
Console.WriteLine("Phone Number...:{0}", _
PhoneList(RowCount, 2))
Else
Console.WriteLine("Name not in list")
Console.ReadKey()
End Sub 4
Yen
RowCount 5
Will 2
Fail
Screen
Enter Name…: Ann

19. Narrative Memory Ann Code True 2 Screen Enter Name…: Ann 1 2 1 Jim
This IF statement compares the SearchName with column one of the PhoneList where row is RowCount. Row 2 column 1 is Ann
This time SearchName does match Ann.
So Found is set to True.
PhoneList 1 2
SearchName
Ann 1
Jim 2
Ann
Found
True 3
Raf
Code
'Searching the array
Dim SearchName As String
Dim Found As Boolean
Dim RowCount As Integer
Console.Clear()
Console.Write("Enter Name.....:")
SearchName = Console.ReadLine( )
Found = False
RowCount = 0
While Found = False And RowCount < 5
RowCount = RowCount + 1
If PhoneList(RowCount, 1) = SearchName Then
Found = True
End If
End While
If Found = True Then
Console.WriteLine("Phone Number...:{0}", _
PhoneList(RowCount, 2))
Else
Console.WriteLine("Name not in list")
Console.ReadKey()
End Sub 4
Yen
RowCount 5
Will 2
Fail
Screen
Enter Name…: Ann

20. Narrative Memory Ann Code True 2 Screen Enter Name…: Ann 1 2 1 Jim
The variables are tested again to see if the while loop should run through again.
Found is no longer = False and so this loop will end.
Note that RowCount is 2 and that row 2 column 2 holds the corresponding phone number.
PhoneList 1 2
SearchName
Ann 1
Jim 2
Ann
Found
True 3
Raf
Code
'Searching the array
Dim SearchName As String
Dim Found As Boolean
Dim RowCount As Integer
Console.Clear()
Console.Write("Enter Name.....:")
SearchName = Console.ReadLine( )
Found = False
RowCount = 0
While Found = False And RowCount < 5
RowCount = RowCount + 1
If PhoneList(RowCount, 1) = SearchName Then
Found = True
End If
End While
If Found = True Then
Console.WriteLine("Phone Number...:{0}", _
PhoneList(RowCount, 2))
Else
Console.WriteLine("Name not in list")
Console.ReadKey()
End Sub 4
Yen
RowCount 5
Will 2
Fail
Screen
Enter Name…: Ann

21. Narrative Memory Ann Code True 2 Screen Enter Name…: Ann
The IF statement checks to see if Found is equal True.
It is. So the Phone number at row (RowCount i.e.2) column (2) is written to the screen.
PhoneList 1 2
SearchName
Ann 1
Jim 2
Ann
Found
Code
True 3
Raf
'Searching the array
Dim SearchName As String
Dim Found As Boolean
Dim RowCount As Integer
Console.Clear()
Console.Write("Enter Name.....:")
SearchName = Console.ReadLine( )
Found = False
RowCount = 0
While Found = False And RowCount < 5
RowCount = RowCount + 1
If PhoneList(RowCount, 1) = SearchName Then
Found = True
End If
End While
If Found = True Then
Console.WriteLine("Phone Number...:{0}", _
PhoneList(RowCount, 2))
Else
Console.WriteLine("Name not in list")
Console.ReadKey()
End Sub 4
Yen
RowCount 5
Will 2
Fail
Screen
Enter Name…: Ann
Number……..:

22. Narrative Memory Fred Code False 5 Screen Enter Name…: Fred
If no match for SearchName had been found in the while loop -Found would have stayed set to False.
The RowCount would have reached 5 and terminated the loop.
Then the message in the Else part if this IF statement would have written Name not in list on the screen.
PhoneList 1 2
SearchName
Fred 1
Jim 2
Ann
Found
Code
False 3
Raf
'Searching the array
Dim SearchName As String
Dim Found As Boolean
Dim RowCount As Integer
Console.Clear()
Console.Write("Enter Name.....:")
SearchName = Console.ReadLine( )
Found = False
RowCount = 0
While Found = False And RowCount < 5
RowCount = RowCount + 1
If PhoneList(RowCount, 1) = SearchName Then
Found = True
End If
End While
If Found = True Then
Console.WriteLine("Phone Number...:{0}", _
PhoneList(RowCount, 2))
Else
Console.WriteLine("Name not in list")
Console.ReadKey()
End Sub 4
Yen
RowCount 5
Will 5
Fail
Screen
Enter Name…: Fred
Name not in list

23. Narrative Memory Ann Code True 2 Screen Enter Name…: Ann
This statement waits for a key to be pressed on the keyboard.
Once the key is pressed this example program ends
PhoneList 1 2
SearchName
Ann 1
Jim 2
Ann
Found
Code
True 3
Raf
'Searching the array
Dim SearchName As String
Dim Found As Boolean
Dim RowCount As Integer
Console.Clear()
Console.Write("Enter Name.....:")
SearchName = Console.ReadLine( )
Found = False
RowCount = 0
While Found = False And RowCount < 5
RowCount = RowCount + 1
If PhoneList(RowCount, 1) = SearchName Then
Found = True
End If
End While
If Found = True Then
Console.WriteLine("Phone Number...:{0}", _
PhoneList(RowCount, 2))
Else
Console.WriteLine("Name not in list")
Console.ReadKey()
End Sub 4
Yen
RowCount 5
Will 2
Fail
Screen
Enter Name…: Ann
Number……..:

24. End of 2D Array example