Linq2Sql: Does HasValue and != null, work the same for nullable types?

Question

Is there any reason why I should choose one of these over the other? Or doesn't it really matter?

var a = data.Cars.Where(ø => ø.LicensePlate != null);

var b = data.Cars.Where(ø => ø.LicensePlate.HasValue);

I have used != null before, but starting to think I should maybe switch, since HasValue kind of reads better. What do you guys think? Is there any difference at all? Other than one character extra? Any performance differences? Sql differences?

Answer 1

No, both statements are the same and you ought to choose whichever one you find more readable.

Something interesting to note is that the compiler will replace null comparisons on a Nullable<T> with a call to HasValue. In other words this:

class Program
{
    static void Main()
    {
        int? i = 0;

        Console.WriteLine(i != null);
        Console.WriteLine(i.HasValue);
    }
}

gets compiled to this:

private static void Main()
{
    int? i = 0;
    Console.WriteLine(i.HasValue);
    Console.WriteLine(i.HasValue);
}