An enumeration that defines three shipping types

public enum ShippingType
{
    UPS_NEXT_DAY,
    UPS_SECOND_DAY,
    UPS_GROUND
}

A statement that uses the enumeration and one of its constants

ShippingType secondDay = ShippingType.UPS_SECOND_DAY;

A method that uses the shipping enumeration as a parameter type

public static double getShippingAmount(ShippingType st)
{
    double shippingAmount = 2.99;
    if (st == ShippingType.UPS_NEXT_DAY)
        shippingAmount = 10.99;
    else if (st == ShippingType.UPS_SECOND_DAY)
        shippingAmount = 5.99;
    return shippingAmount;
}

A statement that calls this method

double shippingAmount =
    getShippingAmount(ShippingType.UPS_SECOND_DAY);
// double shippingAmount2 = getShippingAmount(1); // Wrong type, not allowed