interface implementation

[neha. bajaj]

interface Tester1
{
	int show();
	int demo();
}
class Test1 
{
	public byte show(){					//subtype is valid implementation
		System.out.println("show()");
		return 0;
	}
	public long demo(){					//but how supertype is valid implementation here ?
		System.out.println("demo()");
		return 0;
	}
	public static void main(String[] args) {
	}
}

[neha. bajaj]

Oops.. hadn't implement interface

[Winston Gutkowski]

neha. bajaj wrote:Oops.. hadn't implement interface

So, that's settled is it? I didn't see a question.

Winston

[Matthew Brown]

I think the implied question was "why is this implementation allowed when the return type is wider?".

[neha. bajaj]

Matthew Brown wrote:I think the implied question was "why is this implementation allowed when the return type is wider?".

I don't think widening is working here.I tried but byte is not subtype of int but Byte is subtype of Number.

[Winston Gutkowski]

neha. bajaj wrote:I don't think widening is working here.I tried but byte is not subtype of int but Byte is subtype of Number.

How is converting an int to a byte widening?

My suggestion: explain what you want to do, and ask a question; and we might be able to help.

Winston

[Jesper de Jong]

byte is not a subtype of int, and long is not a supertype of int - there's no inheritance relationship between the primitive types.

[Sirajuddin Khan]

neha. bajaj wrote:

interface Tester1
{
	int show();
	int demo();
}
class Test1 implements Tester1 // If you implement the Interface then the method show
{                              // and demo must be override by the implementer class.
	public byte show(){					
		System.out.println("show()");
		return 0;
	}
	public long demo(){					
		System.out.println("demo()");
		return 0;
	}
	public static void main(String[] args) {
	}
}

for your kind information, please check your code because it is not implement the interface's method so you got compile-time error.
You are doing overloading....

[Winston Gutkowski]

Sirajuddin Khan wrote:please check your code...

Sirajuddin,

Please don't post very long lines in code. I broke yours up this time and I suggest you re-read the UseCodeTags page thoroughly.
This applies whether you are posting your own code or somebody else's.

Thanks.

Winston