car

Class Car

java.lang.Object

car.Car

All Implemented Interfaces:

java.lang.Comparable<Car>

public class Car
extends java.lang.Object
implements java.lang.Comparable<Car>

Class invariants:

• The gas tank does not contain a negative amount of gas.
• The gas tank does not have more gas than the tank capacity.
• For every mile traveled, 1/MPG gallons of gas are used.
• The car is in PARK, FORWARD, or REVERSE gear.

Field Summary

Fields

Modifier and Type	Field and Description
static int	FORWARD
static int	PARK
static int	REVERSE

Constructor Summary

Constructors

Constructor and Description
Car() Create a car that gets 20 mpg and has a tank capacity of 10 gallons

Method Summary

Methods

Modifier and Type	Method and Description
int	compareTo(Car otherCar) compare this car with otherCar to see which one is ahead (i.e.
void	fillTank() Fills the tank to the full capacity.
double	getCapacity()
int	getGear()
double	getLocation()
double	getMPG()
double	getRemainingGas()
void	go(double miles) Go for a specified distance (or as far as the current gas allows) in the current gear
void	refuel(double fuelAmount) Fills the gas tank with the given amount of gas, or enough to fill the tank, whichever is less.
void	setGear(int newGear) Sets the gear that the car will be in.
java.lang.String	toString() Used in printing the car's status.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

PARK

public static final int PARK

See Also:

Constant Field Values

FORWARD

public static final int FORWARD

See Also:

Constant Field Values

REVERSE

public static final int REVERSE

See Also:

Constant Field Values

Constructor Detail

Car

public Car()

Create a car that gets 20 mpg and has a tank capacity of 10 gallons

Method Detail

go

public void go(double miles)

Go for a specified distance (or as far as the current gas allows) in the current gear

precondition: car is in gear and has fuel, miles is non-negative

postcondition:

• for gear = FORWARD:
  • location = min(location' + miles, location' + (remainingFuel' * milesPerGallon))
• for gear = REVERSE:
  • location = max(location' - miles, location' - (remainingFuel' * milesPerGallon))

Parameters:

miles - is the number of miles to go

fillTank

public void fillTank()

Fills the tank to the full capacity.

refuel

public void refuel(double fuelAmount)

Fills the gas tank with the given amount of gas, or enough to fill the tank, whichever is less.

precondition: fuelAmount is non-negative

postcondition: remainingFuel = min(tankCapacity, remainingFuel' + fuelAmount)

Parameters:

fuelAmount - is the amount of fuel to add

getRemainingGas

public double getRemainingGas()

Returns:

the current amount of gas car has

getCapacity

public double getCapacity()

Returns:

the fuel tank capacity

getLocation

public double getLocation()

Returns:

current location of car

getMPG

public double getMPG()

Returns:

miles per gallon rating on car

getGear

public int getGear()

Returns:

current gear

setGear

public void setGear(int newGear)

Sets the gear that the car will be in.

Parameters:

newGear - is the gear to set to.

toString

public java.lang.String toString()

Used in printing the car's status. The format is:
Tank Capacity: <tankCapacity>
MPG: <mpg>
Gas left: <gasLeft>
Gear: <gear>
Location: <location>
where <tankCapacity>, <mpg>, <gasLeft>, and <location> are numbers, but <gear> is a string with one of the following values: {"Park", "Reverse", "Forward"}

Overrides:

toString in class java.lang.Object

compareTo

public int compareTo(Car otherCar)

compare this car with otherCar to see which one is ahead (i.e. which one has gone a further distance.)

Specified by:

compareTo in interface java.lang.Comparable<Car>

Parameters:

otherCar - is the car to which to compare

Returns:

-1 if this otherCar is ahead, 0 if equal, 1 if this car is ahead