how to validate if the value is in the array

public enum SuitType
{
    Hearts, Diamonds, Clubs, Spades, Jokers
}

// note the Enum value 'Joker here: this is not used in this example
// but is there to enable another type of Deck definition
// ... the "US deck," with Jokers, for example

public enum CardValueType
{
    Ace, Two, Three, Four, Five, Six, Seven, Eight, Nine, Ten, Jack, Queen, King, Joker
}

public class Card
{
    // note the private 'set
    public SuitType Suit { private set; get; }
    public CardValueType Value { private set; get; }

    public Card(SuitType suit, CardValueType value)
    {
        Suit = suit;
        Value = value;
    }
}

// note inheritance from List<Card>
public class Deck : List<Card>
{
    public void ShuffleDeck()
    {
        var rnd = new Random(DateTime.Now.Millisecond);
        
        this.OrderBy(order => rnd.Next());
    }
}

// "Classic" or "French" Deck
// four Suits of 13 cards each.

// because we inherit from 'Deck:
// this class also will behave as a List<Card>
public class ClassicDeck : Deck
{
    public ClassicDeck()
    {
        for (int i = 0; i < 4; i++)
        {
            var suit = (SuitType) i;

            for (int j = 0; j < 13; j++)
            {
               this.Add(new Card(suit, (CardValueType)j));
            }
        }
    }
}

// test: put these in a Form's code

// requires Two TextBoxes on the Form, 'textBox1, 'textBox2
// requires a Button on the Form, 'btnTestDeck with its 'Click EventHandler
// connected to the EventHandler shown here

private ClassicDeck TheCurrentDeck;

private void TestDeck(Deck theDeck)
{
    foreach (Card card in theDeck)
    {
        textBox1.AppendText(string.Format("{0}\t{1}\n", card.Value, card.Suit));
    }

    TheCurrentDeck.ShuffleDeck();

    foreach (Card card in theDeck)
    {
        textBox2.AppendText(string.Format("{0}\t{1}\n", card.Value, card.Suit));
    }
}

// run the app, click the button
private void btnTestDeck_Click(object sender, EventArgs e)
{
    textBox1.Clear();
    textBox2.Clear();
    
    TheCurrentDeck = new ClassicDeck();
    
    TestDeck(TheCurrentDeck);
}