Chapter: Reusing Classes

Create two classes, A and B, with default constructors (empty argument lists) that announce themselves. Inherit a new class called C from A, and create a member of class B inside C. Do not create a constructor for C. Create an object of class C and observe the results.

Notice the different output in the two solutions.

In Java:

package chapter.reusingClasses;

class A {
    A() {
        System.out.println("A");
    }
}

class B {
    B() {
        System.out.println("B");
    }
}

class C extends A {
    B b = new B();
}

public class Exercise5 {

    public static void main(String[] args) {

        C c = new C();

    }

}  /* Output:
    A
    B
*///

In Python:

class A:
    def __init__(self):
        print "A"

class B:
    def __init__(self):
        print "B"

class C(A):
    b = B()

C()

# Output:
# B
# A