Will the following code compile? abstract class A { public int do_stuff1() { return 3; } } class B extends A { @Override public int do_stuff1() { return 4; } public int do_stuff2() { return 7; } } class Main { public static void main(String[] args) { //Note the polymorphism: A myB = new B(); myB.do_stuff1(); myB.do_stuff2(); } } No, Class C can't extend one class (B) and implement an interface (1A), it can only do one or the other. No, Class C doesn't correctly override do_stuff2() No, class C cannot be instantiated because it implements an interface. Yes .

1. Will the following code compile?
abstract class A {
public int do_stuff1() {
return 3;
}
}
class B extends A {
@Override
public int do_stuff1() {
return 4;
}
public int do_stuff2() {
return 7;
}
}
class Main {
public static void main(String[] args) {
//Note the polymorphism:
A myB = new B();
myB.do_stuff1();
myB.do_stuff2();
}
}

2. Will the following code compile?
abstract class A {
public int do_stuff1() {
return 3;
}
}
class B extends A {
@Override
public int do_stuff1() {
return 4;
}
public int do_stuff2() {
return 7;
}
}
class Main {
public static void main(String[] args) {
//Note the polymorphism:
A myB = new B();
myB.do_stuff1();
myB.do_stuff2();
}
}

3. No, Class C can't extend one class (B) and implement an interface (1A), it can only do one or the
other. No, Class C doesn't correctly override do_stuff2() No, class C cannot be instantiated
because it implements an interface. Yes