How to combine || operators in condition statement [duplicate]

Answer 1

Unfortunately not, your best bet is to create an extension method

public static bool IsOneOf(this T value, params T[] options)
{
    return options.Contains(value);
}

and you can use it like this:

if (foo.IsOneOf("1", "5", "9"))
{
    ...
}

Being generic, it can be used for any type (int, string etc).