Most checks against an IndexOf value compare it with -1 because 0 is a valid index. Any checks which look for values >
0 ignore the first element, which is likely a bug. If the intent is merely to check inclusion of a value in a string,
List, or an array, consider using the Contains method instead.
This rule raises an issue when an IndexOf value retrieved from a string, List or array is tested against
> 0.
This rule also raises an issue when IndexOfAny, LastIndexOf or LastIndexOfAny from a string is
tested against > 0
Noncompliant Code Example
Dim Color As String = "blue"
Dim Name As String = "ishmael"
Dim Strings As New List(Of String)
Strings.Add(Color)
Strings.Add(Name)
Dim StringArray As String() = Strings.ToArray()
If Strings.IndexOf(Color) > 0 Then ' Noncompliant
' ...
End If
If Name.IndexOf("ish") > 0 Then ' Noncompliant
' ...
End If
If Name.IndexOf("ae") > 0 Then ' Noncompliant
' ...
End If
If Array.IndexOf(StringArray, Color) > 0 Then ' Noncompliant
' ...
End If
Compliant Solution
Dim Color As String = "blue"
Dim Name As String = "ishmael"
Dim Strings As New List(Of String)
Strings.Add(Color)
Strings.Add(Name)
Dim StringArray As String() = Strings.ToArray()
If Strings.IndexOf(Color) > -1 Then
' ...
End If
If Name.IndexOf("ish") >= 0 Then
' ...
End If
If Name.Contains("ae") Then
' ...
End If
If Array.IndexOf(StringArray, Color) >= 0 Then
' ...
End If
