Slighly Different Program

If this is confusing, remember that object oriented programming is supposed to immitate the real world. Think of some objects of the real world, say objects of the class Human. Each object has its own identity (ie. Bob is a different individual from Jill) even though each has parts that have the same name. It is not confusing to talk of "Bill's heart" and "Bill's nose," and "Jill's heart" and "Jill's nose." With "dot notation" this would be Bob.heart, Bob.nose, Jill.heart, and Jill.nose.

Below is a slightly different version of the program.

import java.io.* ;

class Car
{
  . . . .
}

class MilesPerGallon
{
  public static void main( String[] args ) 
  {
    Car car  = new Car( 32456, 32810, 10.6 );
    System.out.println( "Miles per gallon of car 1 is " 
        + car.calculateMPG() );

    car      = new Car( 100000, 100300, 10.6 );
    System.out.println( "Miles per gallon of car 2 is " 
        + car.calculateMPG() );

  }
}