Ambiguity Error.

this code show compilation error(ambiguity), this is absolutely fine.

But, the following code doesn't show any error while compiling(How java can allow this, any one to justify this).




Thanks,
Bennet.

The compile will always use the most specific arguments. Since String is more precise that Object that method is chosen.

How can you say, that "most specific arguments" for a null.

If you say this, it must work for other code also.

This is what i thought, but its not actual reason i suppose.

Thanks,
Bennet

With String and Object, you can say that String is more specific than Object because it is a subclass of Object.

How do you decide which is more specific between String and A ? You can't and neither can the compiler and so it complains.

There is a lot about "overloading" in the Java™ Language Specification; read that section and go to the index and look up overloading, and see what you can find.

Hello,
This is the "Automatic promotion" concept of OOPS. Here String and the class A both are at same level. that means both are extending the Object class.that is why you got error in first program. Coming to the second program, you used String and Object class references as parameters. here the compiler always check for String first, If it is not matched then it will go for Object class reference. I hope you got my point.