I recently wrote a post on declaring arrays in C# and decided to convert it to VB. Below is code for a console app that demonstrates declaring Single Dimension Arrays, Multi Dimension Arrays and Arrays in Arrays, also known as Ragged or Jagged Arrays.
Module Module1
Sub Main()
'single dimension
Dim ages(4) As Integer
ages(0) = 3
ages(1) = 6
ages(2) = 20
ages(3) = 34
ages(4) = 67
Console.WriteLine("Single Dimensional Array")
For ageLoop = 0 To ages.Length - 1
Console.WriteLine(String.Format("Item {0}: {1}", ageLoop, ages(ageLoop)))
Next
Console.Write(vbCrLf & vbCrLf & "Multi Dimensional Array" & vbCrLf)
'multi dimensional
Dim names(1, 1) As String
names(0, 0) = "Andrew"
names(0, 1) = "Bobby"
names(1, 0) = "Susan"
names(1, 1) = "Peter"
Console.WriteLine("Row" + vbTab + "Col" + vbTab + "Value")
For row = 0 To names.GetUpperBound(0)
For col = 0 To names.GetUpperBound(row)
Console.WriteLine(String.Format("{0}{1}{2}{3}{4}", row, vbTab, col, vbTab, names(row, col)))
Next
Next
Console.Write(vbCrLf & vbCrLf & "Array of Arrays" & vbCrLf)
' Array of arrays
Dim days()() As String = New String(1)() {}
days(0) = New String(1) {}
days(0)(0) = "Monday"
days(0)(1) = "Wednesday"
days(1) = New String(3) {}
days(1)(0) = "Tuesday"
days(1)(1) = "Friday"
days(1)(2) = "Saturday"
days(1)(3) = "Sunday"
Console.WriteLine("Row" + vbTab + "Col" + vbTab + "Value")
For row = 0 To days.GetUpperBound(0)
For col = 0 To days(row).GetUpperBound(0)
Console.WriteLine(String.Format("{0}{1}{2}{3}{4}", row, vbTab, col, vbTab, days(row)(col)))
Next
Next
If (System.Diagnostics.Debugger.IsAttached) Then
System.Diagnostics.Debugger.Break()
End If
End Sub
End Module
Below is code for another console app that shows how arrays can be initialised inline with declarations and a way to use For Each loops to iterate the array elements.
Module Module2
Sub Main()
'single dimension
Dim ages() As Integer = New Integer(4) {3, 6, 20, 34, 67}
Console.WriteLine("Single Dimensional Array")
For Each age As Integer In ages
Console.WriteLine(age)
Next
Console.Write(vbCrLf & vbCrLf & "Multi Dimensional Array" & vbCrLf)
'multi dimensional
Dim names(,) As String = New String(1, 1) {{"Andrew", "Bobby"}, {"Susan", "Peter"}}
Console.WriteLine("Row" + vbTab + "Col" + vbTab + "Value")
For Each name As String In names
Console.WriteLine(name)
Next
Console.Write(vbCrLf & vbCrLf & "Array of Arrays" & vbCrLf)
' Array of arrays
Dim days()() As String = { _
New String() {"Monday", "Wednesday"}, _
New String() {"Tuesday", "Friday", "Saturday", "Sunday"} _
}
Console.WriteLine("Row" + vbTab + "Col" + vbTab + "Value")
For Each d() As String In days
For Each day As String In d
Console.WriteLine(day)
Next
Next
If (System.Diagnostics.Debugger.IsAttached) Then
System.Diagnostics.Debugger.Break()
End If
End Sub
End Module
The example application is available from Github here.
