Polymorphism and method overloading

Question

I have a quick and straighforward question:

I have this simple class:

public class A
{
    public void m(Object o)
    {
      System.out.println(\"m         


        

Answer 1

First of all, it actually calls m(Number).

It happens because both methods are applicable, but m(Number) is the most specific method, since any argument of m(Number) can be passed to m(Object), but not vice versa.

If you replace m(Object) by m(String) (or add another method such as m(Date)), compiler would report ambiguity, since the most specific method can't be identified.

See the section Choosing the Most Specific Method in the Java Specification.