Why call to method with null invokes String Parameter and not Object

[Sunny Kumar Kalra]

Hi All,

I have a question in mind :

anyObject.callme(NULL)

callme (String)
callme (Object)

--> invokes callme(String ) and not callme(Object) , Why so ?

[Michael Petrovich]

The informal intuition is that one method is more specific than another if any invocation handled by the first method could be passed on to the other one without a compile-time type error.

In your case you can invoke callme (Object) both with new Object() and new String() parameters without Compile Time Errors. But you can't invoke callme (String) with new Object() without Compile Time Error so the callme (String) is more specific.
For more academic details see http://docs.oracle.com/javase/specs/jls/se5.0/html/expressions.html#15.12.2.5