Java Programming Questions and Answers

Showing 1 - 5 of 5 questions

publicabstractclassAbstractTest 
{publicint getNum() 
    {
        return45;
    }
    publicabstractclassBar 
    {publicint getNum() 
        {
            return38;
        }
    }
    publicstaticvoid main (String [] args) 
    {
        AbstractTest t = new AbstractTest() 
        {
            publicint getNum() 
            {
                return22;
            }
        };
        AbstractTest.Bar f = t.new Bar() 
        {
            publicint getNum() 
            {
                return57;
            }
        };
        
        System.out.println(f.getNum() + " " + t.getNum());
    }
}

what wll be the output?

57 22

45 38

45 57

An exception occurs at runtime.

correct answer a

publicclassHorseTest 
{publicstaticvoid main (String [] args) 
    {
        classHorse 
        {public String name; /* Line 7 */public Horse(String s) 
            {
                name = s;
            }
        } /* class Horse ends */
        
        Object obj = new Horse("Zippo"); /* Line 13 */
        Horse h = (Horse) obj; /* Line 14 */
        System.out.println(h.name);
    }
} /* class HorseTest ends */

what will be the output?

An exception occurs at runtime at line 10

It prints "Zippo"

Compilation fails because of an error on line 7.

Compilation fails because of an error on line 13.

correct answer b

Which constructs an anonymous inner class instance?

Runnable r = new Runnable() { };

Runnable r = new Runnable(public void run() { });

Runnable r = new Runnable { public void run(){}};

System.out.println(new Runnable() {public void run() { }});

correct answer d

Which is true about a method-local inner class?

It must be marked final.

It must be marked abstract.

It must be marked public.

It must be marked static.

correct answer b

classBoo 
{
    Boo(String s) { }
    Boo() { }
}
classBarextendsBoo 
{
    Bar() { }
    Bar(String s) {super(s);}
    void zoo() 
    {
    // insert code here
    }
}
which one create an anonymous inner class from within class Bar?

Boo f = new Boo(24) { };

Boo f = new Bar() { };

Bar f = new Boo(String s) { };

Boo f = new Boo.Bar(String s) { };

correct answer b