Question

Hello there,

So I got an assignment that I just cant get further with. So trying to start from scratch again..

So im supposed to make a class with a UML aswell and a main file.

This is how far ive came, https://imgur.com/a/MGqUN , Thats the car class code and the UML.

This is the assignment

Make a program where you can handle different cars at a car company. The user should be able to choose
do the following:
a) Add cars to an array of Car items.
b) Change car data based on car_id (car_id can be, for example, reg.no)
c) Remove car based on car_id
d) Search for a car brand and list all cars for the search market.
e) Search on year and list all cars for the search year.
f) The program should sum up the value of all cars located at the car company.
g) List all cars in the array of car items
Make a car class that keeps the appropriate data about cars
Make a class of main method where objects are created by the car class. (PS, dont use arraylist, only standard array).

When executing the program, a list of the choices a user can make is displayed in the console of Eclipse
and the user should be able to make a choice and the program should not be closed until the user
choose to end.

So I thought if you could help me out with the car class and the UML so I can get a proper base for the main string.

If you want ur free to do the main string aswell but optional for you.

Greatly appreciate any help!! :)

Kind regards

Answer 1

UML would be like-

Car.java

public class Car {

//data members

private int carId;

private String carModel;

private int carYear;

private double carPrice;

public Car(){

}

// constructor to set data members

public Car(int carId, String carModel, int carYear, double carPrice) {

this.carId = carId;

this.carModel = carModel;

this.carYear = carYear;

this.carPrice = carPrice;

}

//setter and getter methods for data members

public int getCarId() {

return carId;

}

public void setCarId(int carId) {

this.carId = carId;

}

public String getCarModel() {

return carModel;

}

public void setCarModel(String carModel) {

this.carModel = carModel;

}

public int getCarYear() {

return carYear;

}

public void setCarYear(int carYear) {

this.carYear = carYear;

}

public double getCarPrice() {

return carPrice;

}

public void setCarPrice(double carPrice) {

this.carPrice = carPrice;

}

// this method returns car details

public String toString(){

return "Car [cardId= "+this.carId+

", carModel= "+this.carModel+

", carYear= "+this.carYear+

", carPrice= "+this.carPrice+"]";

}

}

CarDemo.java

import java.util.Scanner;

import package2.Book;

public class CarDemo {

private final static int MAX_SIZE=10; //max size of car array (change it a/c to requirement)

private static int currentIndex=0; //represents current index of car array

public static void main(String[] args) {

Car[] carList=new Car[MAX_SIZE]; //Car array to hold cars

Scanner scan=new Scanner(System.in); //Scanner object to read user inputs

int choice;

//execute loop till user enters 8

do{

//display menu

System.out.println("Menu");

System.out.println("1. Add a Car");

System.out.println("2. Change a Car details");

System.out.println("3. Delete a Car");

System.out.println("4. Search for a car brand");

System.out.println("5. Search on year");

System.out.println("6. Total Price");

System.out.println("7. All car in the list");

System.out.println("8.Exit");

System.out.print("Enter choice : "); //ask user to enter choice

choice=scan.nextInt();

//call function according to choice

switch(choice){

case 1:

addCar(carList);

break;

case 2:

changeCar(carList);

break;

case 3:

deleteCar(carList);

break;

case 4:

searchByBrand(carList);

break;

case 5:

searchbyYear(carList);

break;

case 6:

totalPrice(carList);

break;

case 7:

allCars(carList);

break;

case 8:

System.exit(0);

}

}while(choice!=8);

}

private static void addCar(Car[] carList) {

if(currentIndex==MAX_SIZE){ //check if carlist is full else ask for input

System.out.println("Car list is full");

}else{

Scanner scan=new Scanner(System.in);

System.out.print("Enter car id : "); //ask to enter id

int id=Integer.parseInt(scan.nextLine());

for(int i=0;i<currentIndex;i++){ //iterate over carlist to check if car exists

if(carList[i].getCarId()==id){ //if exists, do not allow to add car and return

System.out.println("Car with this id already exists.");

return;

}

}

//else ask to enter model, year and price

System.out.print("Enter car model : ");

String model=scan.nextLine();

System.out.print("Enter car year : ");

int year=Integer.parseInt(scan.nextLine());

System.out.print("Enter car price : ");

double price=Double.parseDouble(scan.nextLine());

carList[currentIndex]=new Car(id,model,year, price); //add car to carList

currentIndex++; //increment current index

}

}

private static void changeCar(Car[] carList) {

if(currentIndex==0){ //check if carlist is empty else ask for input

System.out.println("Car list is empty");

}else{

Scanner scan=new Scanner(System.in);

System.out.print("Enter car id : "); //ask to enter id

int id=Integer.parseInt(scan.nextLine());

for(int i=0;i<currentIndex;i++){ //iterate over carlist to check if car exists

if(carList[i].getCarId()==id){ //If exists,

//ask for new id, model, year and price

System.out.print("Enter new id : ");

id=Integer.parseInt(scan.nextLine());

System.out.print("Enter car model : ");

String model=scan.nextLine();

System.out.print("Enter car year : ");

int year=Integer.parseInt(scan.nextLine());

System.out.print("Enter car model : ");

double price=Double.parseDouble(scan.nextLine());

//set new values

carList[i].setCarId(id);

carList[i].setCarModel(model);

carList[i].setCarYear(year);

carList[i].setCarPrice(price);

return;//return

}

}

//else show error message

System.out.println("Car with this id does not exists.");

}

}

private static void deleteCar(Car[] carList) {

if(currentIndex==0){ //check if carlist is empty else ask for input

System.out.println("Car list is empty");

}else{

Scanner scan=new Scanner(System.in);

System.out.print("Enter car id : "); //ask to enter id

int id=Integer.parseInt(scan.nextLine());

for(int i=0;i<currentIndex;i++){ //iterate over carlist to check if car exists

if(carList[i].getCarId()==id){ //If yes, delete the car

//delete a car by shifting array values

for(int j=i;j<(currentIndex-1);j++){

carList[j]=carList[j+1];

}

currentIndex-=1; //decrement current index

System.out.println("Car deleted");

return; //return

}

}

//else show error message

System.out.println("Car with this id does not exists.");

}

}

private static void searchByBrand(Car[] carList) {

if(currentIndex==0){ //check if carlist is empty else ask for input

System.out.println("Car array is empty");

}else{

Scanner scan=new Scanner(System.in);

System.out.print("Enter car brand : "); //enter brand

String brand=scan.nextLine();

for(int i=0;i<currentIndex;i++){ //iterate over carlist

//if brand matches, print car details

if(carList[i].getCarModel().toLowerCase().contains(brand.toLowerCase())){

System.out.println(carList[i]);

}

}

}

}

private static void searchbyYear(Car[] carList) {

if(currentIndex==0){ //check if carlist is empty else ask for input

System.out.println("Car array is empty");

}else{

Scanner scan=new Scanner(System.in);

System.out.print("Enter year : "); //enter year

int year=Integer.parseInt(scan.nextLine());

for(int i=0;i<currentIndex;i++){ //iterate over carlist

//if year matches, print car details

if(carList[i].getCarYear()==year){

System.out.println(carList[i]); }

}

}

}

private static void totalPrice(Car[] carList) {

if(currentIndex==0){ //check if carlist is empty else ask for input

System.out.println("Car list is empty");

}else{

double total=0;

for(int i=0;i<currentIndex;i++){ //iterate over carlist

total+=carList[i].getCarPrice(); //add price to total

}

System.out.println("Total value of all cars located at the car company = "+total);

}

}

private static void allCars(Car[] carList) {

//iterate over carlist and print all cars

for(int i=0;i<currentIndex;i++){

System.out.println(carList[i]);

}

}

}

OUTPUT-

5. Search on year 6. Total Price 7. All car in the list 8.Exit Enter choice1 Enter car id 125 Enter car model volvO XC45 Enter car year2016 Enter car price 400000 Menu 1 Add a Car 2. Change a Car details 3. Delete a Car 4. Search for a car brand 5. Search on year 6. Total Price 7. All car in the list 8.Exit Enter choiceI Enter car id 126 Enter car model maruti xr4 Enter car year 2011 Enter car price 200000 Menu 1. Add a Car 2. Change a Car details 3. Delete a Car 4. Search for a car brand 5. Search on year 6. Total Price 7. All car in the list

Car Car Car Menu [card1d= [card1d= [card1d= 127, 125, 126, carMode1= carMode1= carMode!= volvo volvo maruti XC601, carYear= 2017, ca r Price= 495000.0] xc45, carYear= 2016, ca r Price= 400000.0] xr4, carYear= 2011, carPrice= 200000.0] 1. Add a Car 2. Change a Car details 3. Delete a Car 4. Search for a car brand 5. Search on year 6. Total Price 7. All car in the list 8.Exit Enter choice 3 Enter car id 123 Car with this id does not exists. Menu 1. Add a Car 2. Change a Car details 3. Delete a Car 4. Search for a car brand 5. Search on year . Total Price 7. All car in the list 8. Exit Enter choice 3 Enter car id 125 Menu 1. Add a Car 2. Change a Car details 3. Delete a Car 4. Search for a car brand

5. Search on year 6. Total Price 7. All car in the list 8.Exit Enter choice 7 Car [card1d= 127, carMode1= volvo XC601, carYear= 2017, ca r Price= 495000.0] Car [card1d= 126, carModel=ma ruti xr4, carYear= 2011, carPrice= 200000.0] Menu 1. Add a Car 2. Change a Car details 3. Delete a Car 4. Search for a car brand 5. Search on year 6. Total Price 7. All car in the list 8.Exit Enter choice4 Enter car brand volvo Car [cardid= 127, carMode1= volvo XC601, carYear= 2017, ca r Price= 495000.0] Menu 1. Add a Car 2. Change a Car details 3. Delete a Car 4. Search for a car brand 5. Search on year 6. Total Price 7. All car in the list 8.Exit Enter choice 5 Enter year: 2017 Car [card1d= 127, carMode1= volvo XC601, carYear= 2017, carPrice= 495000.0]

Menu 1. Add a Car 2. Change a Car details 3. Delete a Car 4. Search for a car brand 5. Search on year 6. Total Price 7. All car in the list 8.Exit Enter choice 8