mock exam errata

[Rishi Yagnik]

Given the following defn which of the defination are valid?
interface I{
void setValue(int i);
int getValue();
}
select all valid answers:
i) interface B extends I{
void increment();
}
ii) abstract class c implements I{
int getValue(){
return 0;
}
abstract void increment();
}
i am not providing u all the option pls tell me my second option is right or wrong?
i think it is right?

Rishi

[Rob Acraman]

It's NEARLY right
Interface methods are implicitly public, and so any class that implements them must also declare them to be public (since sub-classes cannot make anything they inherit less public than it was declared in the super-class).
So, just make getValue() public, like so:

abstract class c implements I{
    public int getValue(){return 0;}
    abstract void increment(); 
}

[N Mukherjee]

Hi Rishi,
IN interface methods are implicitly public
Now , in the abstarct class you are overridding one method
and restricting the access (from public to package )
Hope that helps:-)
regds
NM
------------------
"Knowledge is Power"****************MY SCJP RESOURCES

[Rob Acraman]

Just thought I'd also make mention this:
The question above is very tricky, in that it's really testing you on 2 levels:
- "Explicitly" testing your understanding of abstract classes and interfaces
- A subtler test of "public" and permissions.
These type of questions DO occur in SCJP, so make sure you keep your wits about you.
Good Luck

[Rishi Yagnik]

Thank u
for nice explanation.