Using String.Contains with case-insensitive arguments.

Question

Is there any way to use

Dim Str as String = "UPPERlower"
Str.Contains("UpperLower") and have it return true?

Answer 1

The following will return true

Option Compare Text
Public Class Form1
    Private Sub StartButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim Str As String = "UPPERlower"
        Dim b As Boolean = InStr(Str, "UpperLower")
    End Sub
End Class

Answer 2

That is exactly what I needed. Thank you very much.

Answer 3

What about in C#, besides uppercasing or lowercasing both the target and the source?

Answer 4

Code Snippet

string target = "mello yello";

string find = "Lo";

if (0 <= target.IndexOf(find, StringComparison.InvariantCultureIgnoreCase)) {

  // found

}

else {

  // not found

}

Answer 5

The method I always use is the following (c#):

  Str.ToUpperInvariant().Contains("UpperLower".ToUpperInvariant());