Usage of members in Interface and Abstract

[Balaji Loganathan]

I know we can use define variables in interface and abstract. Can anybody please explain me the actual usage of declaring variables in Interface and Abstract classes.
like
public interface MyInterface {
int x=10;
void hello();
}
and
abstract class {
int a = 10;
abstract public void myhello();
}
Thanks

[CJ Fleck]

i'm not real sure about the interface one. however, the abstract class one i have seen and used before. basically it is so any class that extends this abstract parent class can use that variable. if sub1 and sub2 are classes that extend this abstract class then both of them inherit their parents qualities. this really exemplifies the idea of subclassing.
i am unclear however on what the interface use would be.

[George Pincharoen]

interface variable is public static final
so,it can access from every class that implement it
(see interface Connection in for example of usage)

[Eugene Karpenko]

Fields in an interface are implicitly public, static and final.
On the other hand, fields in an abstract class could have any access modifier, could be static or not, and final or not.