Overriding == operator. How to compare to null? [duplicate]

Answer 1

I've always done it this way (for the == and != operators) and I reuse this code for every object I create:

public static bool operator ==(Person lhs, Person rhs)
{
    // If left hand side is null...
    if (System.Object.ReferenceEquals(lhs, null))
    {
        // ...and right hand side is null...
        if (System.Object.ReferenceEquals(rhs, null))
        {
            //...both are null and are Equal.
            return true;
        }

        // ...right hand side is not null, therefore not Equal.
        return false;
    }

    // Return true if the fields match:
    return lhs.Equals(rhs);
}

"!=" then goes like this:

public static bool operator !=(Person lhs, Person rhs)
{
    return !(lhs == rhs);
}

Edit
I modified the == operator function to match Microsoft's suggested implementation here.