Method overloading and null value [duplicate]

Answer 1

It is a product of overload resolution. Your argument, null, is convertible to both object and int[]. The compiler therefore picks the most specific version, because int[] is more specific than object.

Answer 2

Because int[] is more specific than object, the method with the object-parameter will be ignored. If you would call Method("Some string"), the method with the object-parameter will be called.