Java Programming - Inner Classes

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"Actions speak louder than words."
- (Proverb)

Which is true about an anonymous inner class?

A. It can extend exactly one class and implement exactly one interface.
B. It can extend exactly one class and can implement multiple interfaces.
C. It can extend exactly one class or implement exactly one interface.
D. It can implement multiple interfaces regardless of whether it also extends a class.


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

A. Boo f = new Boo(24) { };
B. Boo f = new Bar() { };
C. Bar f = new Boo(String s) { };
D. Boo f = new Boo.Bar(String s) { };


Which is true about a method-local inner class?

A. It must be marked final.
B. It can be marked abstract.
C. It can be marked public.
D. It can be marked static.


Which statement is true about a static nested class?

A. You must have a reference to an instance of the enclosing class in order to instantiate it.
B. It does not have access to nonstatic members of the enclosing class.
C. It's variables and methods must be static.
D. It must extend the enclosing class.


Which constructs an anonymous inner class instance?

A. Runnable r = new Runnable() { };
B. Runnable r = new Runnable(public void run() { });
C. Runnable r = new Runnable { public void run(){}};
D. System.out.println(new Runnable() {public void run() { }});

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