Visual Basic/Error Handling

Error handling in Visual Basic, an outline:

On Error Goto <Label>
On Error Goto 0
On Error Resume Next
If Err.Number = 0
If Err.Number <> 0
Resume
Resume <Label>
Resume Next
Err.Description
Err.Raise <Number>

Suppressing the error and detecting it using the non-zero error numberː

Set MyCollection = New Collection
MyCollection.Add "Item", "Item"
On Error Resume Next
MyCollection.Add "Item", "Item" 'This result in an error
MyErrNumber = Err.Number
On Error Goto 0 'Restore the absence of error handling
If MyErrNumber <> 0 Then
  'Error occurred
  MsgBox "Item already present in the collection."
End If

Creating an error handlerː

Sub Test()
  On Error Goto ErrorHandler
  ...
  Exit Sub

ErrorHandler:
  ...
End Sub

Creating an error handler that differentiates per error numberː

Sub Test()
  On Error Goto ErrorHandler
  ...
  Exit Sub

ErrorHandler:
  Select Case Err.Number
  Case 0
    'No error
  Case 5
    '...
  Case Else
    '...
  End Select
End Sub