Question

Use an accessor and mutator as follows:

• Remove the addFuel method from class Car
• Replace the call to addFuel in the main program with a call to the accessor and mutator for the fuel amount to achieve the same effect (add 5 gallons of fuel to the existing fuel in the Toyota Camry).
• Test your program again to make sure it works and produces the same output.

Part 2: Add functions to remove duplicate code

* In the main program, there should be 2 places where you are calling printInfo()all 3 cars in row. Define and call a function named printAllCarsInfo() in the main program class to call printInfo() for all 3 cars, and replace the 2 uses with function calls.

* Similarly, in the main program there should be 2 places where you are driving all 3 cars for a certain number of miles. Define and use a function to replace these with function calls. Hint: Your function will need to take a parameter.

Test your program again to make sure it still produces the same output.

Main program:

import java.util.Scanner;

class MainProgram
{
static Car honda, toyota, ford;
public static void main(String[] args)
{
System.out.println("Program 12");

Scanner in=new Scanner(System.in);

honda=new Car("Honda Civic",3000);
toyota=new Car("Toyota Camry",3400);
ford=new Car(" Ford F-150",5000);

honda.drive(10);
toyota.addFuel(5);
toyota.drive(10);
ford.drive(10);

honda.printInfo();
toyota.printInfo();
ford.printInfo();

System.out.println("How many miles is your roadtrip?");

int miles=in.nextInt();

honda.drive(miles);
toyota.drive(miles);
ford.drive(miles);
honda.printInfo();
toyota.printInfo();
ford.printInfo();
}
}

  

Class Car:

public class Car
{
  
private String model;
private double mpg;
private double milesDriven;
private double fuelGallons;
  
Car (String carModel, double weight)
{


  
model = carModel;
milesDriven = 7;
fuelGallons = 15;
if (weight>4000)
mpg = 20;
else
mpg = 30;


}
void addFuel(int noOfGallons)
{
fuelGallons += noOfGallons;
}
double milesLeft()
{
  
return mpg*fuelGallons;
}
void drive(int noOfMiles)
{
  
if (noOfMiles>milesLeft())
{
milesDriven+=milesLeft();
fuelGallons-=milesLeft()/mpg;
}
else
{
milesDriven+=noOfMiles;
  
fuelGallons-=noOfMiles/mpg;
}
  

  
}
void printInfo()
{

if(fuelGallons<=0)
{
  
System.out.println("The " + model + "has driven "+milesDriven+"miles and");
System.out.println("is out of gas");
}
else if(fuelGallons>=0)
{
System.out.println("The"+" "+ model +"has driven"+" "+milesDriven+"miles and");
System.out.println(" "+model+" "+"has"+" "+String.format("%.1f",fuelGallons)+" gallons left");
}
}
public String getModel()
{
return model;
}
public double getMpg()
{
return mpg;
}
public double getMilesDriven()
{
return milesDriven;
}
public double getFuelGallons()
{
return fuelGallons;
}
}

Answer 1

thanks for the question, here is the updated code, changes are marked and commented. Let me know for any changes or modifications.

===============================================================================================

import java.util.Scanner;



public class MainProgram {



    static Car honda,toyota,ford;



    public static void main(String[] args) {



        System.out.println("Program 12");

        Scanner in = new Scanner(System.in);



        honda =new Car("Honda Civic",3000);

        toyota =new Car("Toyota Camry",3400);

        ford=new Car("Ford F-150",5000);



        honda.drive(10);

        double fuel = toyota.getFuelGallons(); // updated

        toyota.setFuelGallons(fuel+5); // updated

        toyota.drive(10);

        ford.drive(10);



        printAllCarsInfo(honda,toyota,ford); // updated



        System.out.println("How many miles is your roadtrip?");

        int miles = in.nextInt();

        honda.drive(miles);

        toyota.drive(miles);

        ford.drive(miles);



        printAllCarsInfo(honda,toyota,ford); // updated



    }



    // new method added

    public static void printAllCarsInfo(Car car1, Car car2, Car car3){

        car1.printInfo();

        car2.printInfo();

        car3.printInfo();

    }

}

public class Car {



    private String model;

    private double mpg;

    private double milesDriven;

    private double fuelGallons;



    Car(String carModel, double weight) {

        model=carModel;

        milesDriven=7;

        fuelGallons=15;

        if(weight>4000){

            mpg=20;

        }else{

            mpg=30;

        }

    }


    // updated code
    public void setFuelGallons(double fuelGallons) {

        this.fuelGallons = fuelGallons;

    }



    double milesLeft(){

        return mpg*fuelGallons;

    }



    void drive(int noOfMiles){

        if(noOfMiles>milesLeft()){

            fuelGallons-=milesLeft()/mpg;

        }else{

            milesDriven+=noOfMiles;

            fuelGallons-=noOfMiles/mpg;

        }

    }



    void printInfo(){

        if(fuelGallons>=0){

            System.out.println("The "+model+" has driven "+milesDriven+" miles and ");

            System.out.println(" "+model+" has "+String.format("%.1f",fuelGallons)+" gallons left");

        }

    }



    public String getModel() {

        return model;

    }



    public double getMpg() {

        return mpg;

    }



    public double getMilesDriven() {

        return milesDriven;

    }



    public double getFuelGallons() {

        return fuelGallons;

    }

}