Compare strings

[staticbob]

Guys,

How can I see if a string containing a single name, is contained within a longer string containing lots of names ?

Bob

[jmcilhinney]

In .NET 2.0 the String class has a Contains method. In earlier versions you make use of the fact that String.IndexOf returns -1 if the specified substring is not contained in the string.

[staticbob]

Thanks John. This works fine as I'm still on 1.1.

If cb_rfiissueto.Text.IndexOf(tb_distribution.Text) < 0 Then
                    'Not in distrib
                    RaiseEvent MailOKChange(pb_MAILYES.Visible, cb_rfiissueto.Text, pb_MAILYES.Visible)
                Else
                    'In distrib
                    RaiseEvent MailOKChange(pb_MAILYES.Visible, cb_rfiissueto.Text, False)
                End If

Bob

[gigemboy]

You can also use Regex, with the .IsMatch method with the name you want to find, it will return true if found....

Dim MyString As String = "John Bob MyName Frank"
        Dim Regex As New System.Text.RegularExpressions.Regex(" MyName ")
        If Regex.IsMatch(MyString) = True Then
            MessageBox.Show("Found it!")
        Else
            MessageBox.Show("Didnt Find it!")
        End If

[Libero]

Hiya! I was searching for function to find and replace string and found this thread. Theere is one interesting thing with this way of findning strings. First, lets run this code:

Dim text As String
        text = "This is my string"

        If text.Contains("") Then
            MsgBox("Found")
        Else
            MsgBox("Not found")
        End If

Same thing with this:

Dim MyString As String = "John Bob MyName Frank"
        Dim Regex As New System.Text.RegularExpressions.Regex("")
        If Regex.IsMatch(MyString) = True Then
            MessageBox.Show("Found it!")
        Else
            MessageBox.Show("Didnt Find it!")
        End If

This code will return Found. Is that a proper way to code? Im in deep need of a way to easy compare 2 strings. And i cant use this one since it thinks an empty string is the same as any string. Any idea from some clever boy??

[Atheist]

I dont see why you'd want to see if a string contains an empty string using IndexOf/Contains...that just sounds strange.
If you want to know if a string equals an empty string why not do a normal comparison?

If text = String.Empty Then
 
End If

or

If text.Equals(String.Empty) Then
 
End If

[Libero]

No, i just want to know if "my" can be found in "this is my string". I dont want my code to say that an empty or a string with space " " is the same as "this is my string". Hehe this sounds crazy, i know.

[Atheist]

No, i just want to know if "my" can be found in "this is my string"

Dim text As String = "this is my string"
If text.Contains("my") Then
    MessageBox.Show("yeah!")
End If

[jmcilhinney]

No, i just want to know if "my" can be found in "this is my string". I dont want my code to say that an empty or a string with space " " is the same as "this is my string". Hehe this sounds crazy, i know.

By definition every string contains the empty string as a substring. If you don't want to look for an empty string then don't. Simply test your substring first to see if it's an empty string and if it is then don't even search for it.