java code:: Car

We're going to work with a motor pool in the next few lessons, and we'll start with a Car class.

Write a class Car. The purpose of a Car object is to represent a single automobile in a motor pool, such as a taxi service. The Car class has the following specification:

instance variable of type String for the car's identifier

instance variable of type int for the car's total miles

instance variable of type int for the car's total fuel consumption (we'll consider only planet-killing fossil fuel consuming evil cars for this exercise)

three constructors

a no-argument constructor

a constructor that takes a single String parameter representing the car's identifier

a constructor that takes three parameters, one for the identifier, a second parameter for the car's initial mileage, and a third parameter for the car's initial fuel consumption

accessors

getters for all instance variables:

getMiles

getFuelUsed

getIdentifier

double getMPG() that returns the current lifetime MPG for the car

int compareMPG(Car otherCar) returns

a negative value (exact value doesn't matter--only that it be less than zero) if the current car gets fewer miles per gallon than otherCar

a positive number (exact value doesn't matter--only that it be greater than zero) if the current car gets more miles per gallon than otherCar

0 if the two cars have exactly the same MPG (given that MPG is a double number, this will probably occur relatively infrequently)

toString that returns something similar to "Car [identifier=Ford1950, miles=160000, fuelUsed=16000]"

mutators

setters for all instance variables

setMiles

setFuelUsed

setIdentifier

void addFuel(int fuelAmount)

void addMiles(int milesTraveled)

Tester

Write a class CarTester having just a main method that

creates 3 Car objects (let's call them car1 and car2a and car2b)

each Car object should be created with a different constructor

each method should be tested at least once with one car

addFuel and addMiles should be used for car2a so that is gets the same miles per gallon as car2b

to make sure that all the possible relations of two car MPGs are calculated correctly, test compareMPG for

(car1, car2a),

(car2b, car1)

(car2a, car2b)

Grading Elements

class name, all constructors, all method names, all method signatures and return types are correct

constructors, getters and setters perform correct operation, return correct values

MPG calculated correctly

accessors do not modify object state

addFuelUsed, addMiles perform correct operation

compareMPG returns proper values