Why is this an issue?

Marking a method with the Pure attribute indicates that the method doesn’t make any visible state changes. Therefore, a Pure method should return a result otherwise it indicates a no-operation call.

Using Pure on a void method is either by mistake or the method is not doing a meaningful task.

How to fix it

Code examples

Noncompliant code example

Class Person
    Private age As Integer

    <Pure> ' Noncompliant: The method makes a state change
    Private Sub ConfigureAge(ByVal age As Integer)
        Me.age = age
    End Sub

    <Pure>
    Private Sub WriteAge() ' Noncompliant
        Console.WriteLine(Me.age)
    End Sub

End Class

Compliant solution

Class Person
    Private age As Integer

    Private Sub ConfigureAge(ByVal age As Integer)
        Me.age = age
    End Sub

    <Pure>
    Private Function Age() As Integer
        Return Me.age
    End Function

    ' or remove Pure attribute from the method

    Private Sub WriteAge()
        Console.WriteLine(Me.age)
    End Sub

End Class

Resources

Documentation

• Microsoft Learn - PureAttribute Class