using regex to validate input formatting in C#

Question

This is a super basic question (I am brain dead today):

How do I validate in input using regexes, to see: 1) if the input is in a certain form 2) if the input is all caps (just casting the input to caps is not feasible for this)

I want ot make sure my inputs are in the form XX_XX. Here isi what I have:

public bool IsKosher(string input)
{
    Regex r = new Regex(input);
    if(r.Matches([A-Z]_[A-Z]))
    {
        return true;
    }
    return false;     
}

Any ideas why it's not compiling?

Thank you!

Answer 1

You are missing double quotes, you put parameters in wrong places, and you do not need an if statement:

public bool IsKosher(string input) {
    return Regex.IsMatch(input, "[A-Z]{2}_[A-Z]{2}");
}