Public class Car {

public void m1 () {

System. out. println ("car 1");

}

â

public void m2 () {

System. out. println ("car 2");

}

â

public String toString () {

return "vroom";

}

}

public class Truck extends Car {

public void m1 () {

System. out. println ("truck 1");

}

}

And assuming that the following variables have been declared:

Car mycar = new Car ();

Truck mytruck = new Truck ();

What is the output from the following statements?

a. Sound F/X System. out. println (mycar);

b. mycar. m1 ();

c. mycar. m2 ();

d. System. out. println (mytruck);

e. mytruck. m1 ();

f. mytruck. m2 ();

The Following are the outputs:

a. vroom

b. car 1

c. car 2

d. vroom

e. truck 1

f. car 2

Explanation:

The first statement System. out. println (mycar); prints an instance of the Car object my car which calls the toString () method.

The second statement mycar. m1 (); Calls the method m1 () which prints car1

The third statement mycar. m2 (); calls the method m2 () which prints car2

Then another class is created Truck, and Truck inherits all the methods of Car since it extends Car. Truck has a method m1 () which will override the inherited method m1 () from the Car class.

The fourth statement System. out. println (mytruck); will print print vroom just as the first statement since it inherits that method toString ()

The fifth statement calls m1 () in the Truck class hence prints Truck 1

Finally the sixth statement will print car 2 because it also inherited that method and didnt overide it.