Question

I’m using a linq query where i do something liike this:

viewModel.REGISTRATIONGRPS = (From a In db.TABLEA
    Select New SubViewModel With {
    .SOMEVALUE1 = a.SOMEVALUE1,
    ...
    ...
    .SOMEVALUE2 = If(commaseparatedstring.Contains(a.SOMEVALUE1), True, False)
    }).ToList()

Now my Problem is that this does’n search for words but for substrings so for example:

commaseparatedstring = “EWM,KI,KP”
SOMEVALUE1 = “EW”

It returns true because it’s contained in EWM?

What i would need is to find words (not containing substrings) in the comma separated string!

Answer 1

Option 1: Regular Expressions

Regex.IsMatch(commaseparatedstring, @"\b" + Regex.Escape(a.SOMEVALUE1) + @"\b")

The \b parts are called “word boundaries” and tell the regex engine that you are looking for a “full word”. The Regex.Escape(...) ensures that the regex engine will not try to interpret “special characters” in the text you are trying to match. For example, if you are trying to match "one+two", the Regex.Escape method will return "one\+two".

Also, be sure to include the System.Text.RegularExpressions at the top of your code file.

See Regex.IsMatch Method (String, String) on MSDN for more information.

Option 2: Split the String

You could also try splitting the string which would be a bit simpler, though probably less efficient.

commaseparatedstring.Split(new Char[] { ',' }).Contains( a.SOMEVALUE1 )