Catching Exceptions Without a Variable

You do not always need to specify a variable in the Catch block. This can be the case in which you want to take the same action independently from the exception that occurred. For example, consider the following code:

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Try
    Dim result As String =
        My.Computer.FileSystem.ReadAllText("C:MyFile.txt")
Catch ex As Exception
    Console.WriteLine("A general error occurred")
End Try

The ex variable is not being used and no specific exceptions are handled. So the preceding code can be rewritten as follows, without the ex variable:

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Try
    Dim result As String =
        My.Computer.FileSystem.ReadAllText("C:MyFile.txt")
Catch
    Console.WriteLine("A general error occurred")
End Try

Whichever exception occurs, the code shows the specified message. This also works with regard to the rethrow technique. The following code simply rethrows the proper exception to the caller:

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Try
    Dim result As String =
        My.Computer.FileSystem.ReadAllText("C:MyFile.txt")
Catch
    Throw
End Try