interface help

[akhter wahab]

public interface GroupedInterface extends Interface1,
                                        Interface2, Interface3 {

   // constant declarations
   double E = 2.718282;  // base of natural logarithms

   // method signatures
   void doSomething (int i, double x);
   int doSomethingElse(String s);

}

public interface GroupedInterface implements Interface1,
                                        Interface2, Interface3 {

   // constant declarations
   double E = 2.718282;  // base of natural logarithms

   // method signatures
   void doSomething (int i, double x);
   int doSomethingElse(String s);

}

i just saw that interface can extends from multiple interfaces as it can implements multiple interfaces

can some one elaborate what is the difference in between both of the above sample code

means why we extends multiple or why we implements multiple

[Aditya Jha]

akhter wahab wrote:can some one elaborate what is the difference in between both of the above sample code

You mean other than the fact that the one with 'implements' will not even compile?

An interface can only extend other interfaces. 'implements' keyword cannot be used in this case.

[Matthew Brown]

Have you tried them? The difference is that the first compiles and the second doesn't.

Classes can extend classes. Interfaces can extend interfaces. Classes can implement interfaces. But you can't have an interface implement an interface.

Edit: 3 seconds late!

[akhter wahab]

Matthew Brown wrote:Have you tried them? The difference is that the first compiles and the second doesn't.

Classes can extend classes. Interfaces can extend interfaces. Classes can implement interfaces. But you can't have an interface implement an interface.

Edit: 3 seconds late!

interface aClass {

}

interface bClass {

}

public class cClass implements aClass,bClass{
    public static void main(String[] args) {
        System.out.println("i m here");
    }

}

 output 

run:
i m here
BUILD SUCCESSFUL (total time: 0 seconds)

then why its working

[Matthew Brown]

akhter wahab wrote:
then why its working

Because there you have a class implementing an interface. Which is allowed, as I said.

[akhter wahab]

Matthew Brown wrote:

akhter wahab wrote:
then why its working

Because there you have a class implementing an interface. Which is allowed, as I said.

sorry dude every single question was just like a joke... infect i am out of mind today thanks for your patience