Thread: I have problem a colections

Could someone guide me how to make printsortedCars
line 32

Code: https://pastebin.com/QqbHtMGj

package myPackage.exam.colections;
 
import java.util.*;
 
public class Task2 {
    static Car BMW = new Car(true, 2005, 2, 1, 22000.0D);
    static Car AUDI = new Car(false, 2020, 1, 2, 604900.0D);
    static Car MERCEDES_BENZ = new Car(true, 2015, 3, 3, 75000.0D);
    static Car BMW_2 = new Car(true, 2003, 2, 4, 150000.0D);
    static Car FERRARI = new Car(true, 2020, 3, 5, 1230000.0D);
    static Car KIA = new Car(false, 2008, 2, 6, 13000.0D);
    static Car FORD = new Car(false, 2011, 2, 7, 8599.99D);
    static Car MCLAREN = new Car(true, 2018, 3, 8, 1700000.0D);
    static Car SKODA = new Car(false, 2001, 1, 9, 14000.0D);
    static Car DACIA = new Car(false, 1998, 1, 10, 6000.0D);
    private static final List<Car> carlist;
 
    public Task2() {
    }
 
 
    public static List<Car> getCarList() {
        Iterator var0 = carlist.iterator();
        if (var0.hasNext()) {
            Car c = (Car)var0.next();
            return (List)c;
        } else {
            return null;
        }
    }
 
    public static void printsortedCars() {
        //Print a list of cars to the console (you have to make the list yourself, preparing GOOD test data is part of the task)
        //the list should be sorted by attributes in the following order:
        //- exclusive cars are to be at the beginning of the list
        //- the newest cars, with the highest year of production, are to be displayed before older cars
        //- cars with higher equipment level are to be displayed before cars with lower equipment level
        //- more expensive cars should be displayed before cheaper cars
 
    }
 
    public static void printCarsToValueAndLevelOfEquipment(double maxValue, int levelOfEquipment) {
        // Business context: a customer goes to a used car dealership website and wants to see cars up to a certain "maxValue"
        // and having a specific equipment level e.g.: level 2 = car has air conditioning, and level 1 car has no air conditioning etc.
        //TASK: Filter and then list the cars from the cheapest to the most expensive from a list of cars
        //todo here the task
        for(Car a : carlist){
            System.out.println(a);
        }
        Collections.sort(carlist);
 
    }
 
    public static void addCardToList() {
        //todo
    }
 
    public static void removeCarFromList() {
        //todo
    }
 
    public static void printCarListAfterSomeModification() {
        //add 2-3 new cars to the list
        //remove 1-2 cars from the list
        // display the list
    }
 
    static {
        carlist = new LinkedList(Arrays.asList(BMW, AUDI, MERCEDES_BENZ, BMW_2, FERRARI, KIA, FORD, MCLAREN, SKODA, DACIA));
    }
 
    public static void main(String[] args) {
        printCarsToValueAndLevelOfEquipment(1,2);
        System.out.println(carlist);
    }
}
 
 
//Car.java
 
package myPackage.exam.colections;
 
 
public class Car implements Comparable<Car> {
    boolean isExclusive;
    int yearOfProduction;
    int levelOfEquipment;
    int id;
    double value;
 
    public Car(boolean isExclusive, int yearOfProduction, int levelOfEquipment, int id, double value) {
        this.isExclusive = isExclusive;
        this.yearOfProduction = yearOfProduction;
        this.levelOfEquipment = levelOfEquipment;
        this.id = id;
        this.value = value;
    }
 
    public boolean getExclusive() {
        return this.isExclusive;
    }
 
    public Integer getYear() {
        return this.yearOfProduction;
    }
 
    public Integer getlevel() {
        return this.levelOfEquipment;
    }
 
    public Integer getId() {
        return this.id;
    }
 
    public double getvalue() {
        return this.value;
    }
 
    public int compareTo(Car o) {
        return 0;
    }
}

Yes, it is but I don't know how to go about it

When I want the console to list my cars, this pops up, how do I fix it?

Console:
myPackage.exam.colections.Car@3ac3fd8b
myPackage.exam.colections.Car@5594a1b5
myPackage.exam.colections.Car@6a5fc7f7
myPackage.exam.colections.Car@3b6eb2ec
myPackage.exam.colections.Car@1e643faf
myPackage.exam.colections.Car@6e8dacdf
myPackage.exam.colections.Car@7a79be86
myPackage.exam.colections.Car@34ce8af7
myPackage.exam.colections.Car@b684286
myPackage.exam.colections.Car@880ec60

Now I have a problem with displaying cars according to price and according to equipment level. I made scanners, I give variables, but in class printCardToValueAndLevelOfEquipment I don't know how in if to add cars value, Car.value doesn't work

   public static void printCarsToValueAndLevelOfEquipment(Scanner maxValue, Scanner levelOfEquipment) {
        // Business context: a customer goes to a used car dealership website and wants to see cars up to a certain "maxValue"
        // and having a specific equipment level e.g.: level 2 = car has air conditioning, and level 1 car has no air conditioning etc.
        //TASK: Filter and then list the cars from the cheapest to the most expensive from a list of cars
        //todo here the task
        for(Car a : carlist){
            if()
            System.out.println(a);
        }
        Collections.sort(carlist);
 
    public static void main(String[] args) {
        System.out.println("Enter maxValue: ");
        Scanner maxValue = new Scanner(System.in);
 
        double m = maxValue.nextDouble();
 
        System.out.println("Enter levelOfEquipment");
        Scanner levelOfEquipment = new Scanner(System.in);
 
        int l = levelOfEquipment.nextInt();
 
        System.out.println();
        printCarsToValueAndLevelOfEquipment(maxValue,levelOfEquipment);
 
    }
}

The purpose of the scanner is to enter the MaxValue of the cars and then in the console pop up cars up to a given amount, if I enter the amount of 2000, only cars up to 2k will be displayed, the same with levelofequipment

--- Update ---

package myPackage.exam.colections;
 
import java.util.*;
 
public class Task2 {
    static Car BMW = new Car(true, 2005, 2, 1, 22000.0D);
    static Car AUDI = new Car(false, 2020, 1, 2, 604900.0D);
    static Car MERCEDES_BENZ = new Car(true, 2015, 3, 3, 75000.0D);
    static Car BMW_2 = new Car(true, 2003, 2, 4, 150000.0D);
    static Car FERRARI = new Car(true, 2020, 3, 5, 1230000.0D);
    static Car KIA = new Car(false, 2008, 2, 6, 13000.0D);
    static Car FORD = new Car(false, 2011, 2, 7, 8599.99D);
    static Car MCLAREN = new Car(true, 2018, 3, 8, 1700000.0D);
    static Car SKODA = new Car(false, 2001, 1, 9, 14000.0D);
    static Car DACIA = new Car(false, 1998, 1, 10, 6000.0D);
    private static final List<Car> carlist;
 
    public Task2() {
    }
 
 
    public String getCarList() {
        return toString();
    }
 
    public static void printsortedCars() {
        //Wypisz na konsolę listę aut (listę należy zrobić samodzielnie, przygotowanie DOBRYCH danych testowych jest cześcią zadania)
        //lista ma być posotrowana po atrybutach w następującej kolejności:
        //- auta ekskluzywne mają znajdować się na początku listy
        //- auta najnowsze, o najwyższym roku produkcji, mają być wyświetlane przed autami starszymi
        //- auta o wyższym poziomie wyposażenia mają być przed autami o niższym poziomie wyposażenia
        //- auta droższe mają być wyświetlane przed tańszymi
    }
 
    public static void printCarsToValueAndLevelOfEquipment(Scanner maxValue, Scanner levelOfEquipment) {
        //Kontekst biznesowy: klient wchodzi na stronę salonu samochodów używanych i chce zobaczyć auta do pewnej kwoty "maxValue"
        // oraz mające konkretny poziom wyposażenia np: poziom 2 = auto ma klimatyzację, a poziom 1 auto klimatyzacji nie ma itp
        //ZADANIE: wyfiltruj a następnie wypisz auta od najtańszego do najdroższego z listy aut
        //todo tutaj wykonaj zadanie
        for(Car a : carlist){
            if()
            System.out.println(a);
        }
        Collections.sort(carlist);
 
    }
 
    public static void addCardToList() {
        //todo
    }
 
    public static void removeCarFromList() {
        //todo
    }
 
    public static void printCarListAfterSomeModification() {
        //dodaj 2-3 nowe auta do listy
        //usuń z listy 1-2 auta
        // wyświetl listę
    }
 
    static {
        carlist = new LinkedList(Arrays.asList(BMW, AUDI, MERCEDES_BENZ, BMW_2, FERRARI, KIA, FORD, MCLAREN, SKODA, DACIA));
    }
 
    public static void main(String[] args) {
        System.out.println("Enter maxValue: ");
        Scanner maxValue = new Scanner(System.in);
 
        double m = maxValue.nextDouble();
 
        System.out.println("Enter levelOfEquipment");
        Scanner levelOfEquipment = new Scanner(System.in);
 
        int l = levelOfEquipment.nextInt();
 
        System.out.println();
        printCarsToValueAndLevelOfEquipment(maxValue,levelOfEquipment);
 
    }
}
 
 
 
package myPackage.exam.colections;
 
 
public class Car implements Comparable<Car> {
    boolean isExclusive;
    int yearOfProduction;
    int levelOfEquipment;
    int id;
    double value;
 
    public Car(boolean isExclusive, int yearOfProduction, int levelOfEquipment, int id, double value) {
        this.isExclusive = isExclusive;
        this.yearOfProduction = yearOfProduction;
        this.levelOfEquipment = levelOfEquipment;
        this.id = id;
        this.value = value;
    }
 
    public boolean getExclusive() {
        return this.isExclusive;
    }
 
    public Integer getYear() {
        return this.yearOfProduction;
    }
 
    public Integer getlevel() {
        return this.levelOfEquipment;
    }
 
    public Integer getId() {
        return this.id;
    }
 
    public double getvalue() {
        return this.value;
    }
 
    public int compareTo(Car o) {
        return 0;
    }
 
   // public String toString() {
    //return isExclusive + "" + yearOfProduction + "" + levelOfEquipment + "" + id + "" + value;
  //  }
 
    public String toString() {
        return this.isExclusive + " " + this.yearOfProduction + " " + this.levelOfEquipment + " " + this.id + " " + this.value;
    }
}

The purpose of the loop is to output the data information about the cars of the list.

Unless I'm misunderstanding it and doing it wrong as you would. Because I don't understand your answer

--- Update ---

I wanted to make in if that if maxValue(e.g. we typed 10000 into the consola) > value (from the list) then the consola prints cars that cost up to 10000

--- Update ---

Do you understand? I enter 1000 in the console and it lists all cars that cost up to 1000, I enter equipment level 2 and it lists cars that have equipment level 2

Originally Posted by Norm

You can use the Scanner class to read that number from the console outside of the printCarsToValueAndLevelOfEquipment method.
Then pass that number to the method as an argument.

But I have it made

Then show me what you would change if you did

I keep trying but I don't know how to add value from cars list to if.

Because I don't know if you understand what he's trying to do.

Scanner I created in order to create a variable, which then in a loop will check the value of vehicles and if I enter the value of 20000 will write me only vehicles to this amount

Now in the loop it gives an error and intelijj wants to change getDesiredvalue from double to boolean

Yes I know that getDesiredValue is as example

package myPackage.exam.colections;
 
import java.util.*;
 
public class Task2 {
    static Car BMW = new Car(true, 2005, 2, 1, 22000.0D);
    static Car AUDI = new Car(false, 2020, 1, 2, 604900.0D);
    static Car MERCEDES_BENZ = new Car(true, 2015, 3, 3, 75000.0D);
    static Car BMW_2 = new Car(true, 2003, 2, 4, 150000.0D);
    static Car FERRARI = new Car(true, 2020, 3, 5, 1230000.0D);
    static Car KIA = new Car(false, 2008, 2, 6, 13000.0D);
    static Car FORD = new Car(false, 2011, 2, 7, 8599.99D);
    static Car MCLAREN = new Car(true, 2018, 3, 8, 1700000.0D);
    static Car SKODA = new Car(false, 2001, 1, 9, 14000.0D);
    static Car DACIA = new Car(false, 1998, 1, 10, 6000.0D);
    private static final List<Car> carlist;
 
    public String getCarList() {
        return toString();
    }
 
    public static void printsortedCars() {
        //Wypisz na konsolę listę aut (listę należy zrobić samodzielnie, przygotowanie DOBRYCH danych testowych jest cześcią zadania)
        //lista ma być posotrowana po atrybutach w następującej kolejności:
        //- auta ekskluzywne mają znajdować się na początku listy
        //- auta najnowsze, o najwyższym roku produkcji, mają być wyświetlane przed autami starszymi
        //- auta o wyższym poziomie wyposażenia mają być przed autami o niższym poziomie wyposażenia
        //- auta droższe mają być wyświetlane przed tańszymi
    }
 
    public static void printCarsToValueAndLevelOfEquipment(Scanner maxValue) {
        //Kontekst biznesowy: klient wchodzi na stronę salonu samochodów używanych i chce zobaczyć auta do pewnej kwoty "maxValue"
        // oraz mające konkretny poziom wyposażenia np: poziom 2 = auto ma klimatyzację, a poziom 1 auto klimatyzacji nie ma itp
        //ZADANIE: wyfiltruj a następnie wypisz auta od najtańszego do najdroższego z listy aut
        //todo tutaj wykonaj zadanie
        for(Car aCar : carlist){
            if(aCar.getValue())
            System.out.println(aCar);
        }
        Collections.sort(carlist);
 
    }
 
    public static void addCardToList() {
    }
 
    public static void removeCarFromList() {
        //todo
    }
 
    public static void printCarListAfterSomeModification() {
        //dodaj 2-3 nowe auta do listy
        //usuń z listy 1-2 auta
        // wyświetl listę
    }
 
    static {
        carlist = new LinkedList(Arrays.asList(BMW, AUDI, MERCEDES_BENZ, BMW_2, FERRARI, KIA, FORD, MCLAREN, SKODA, DACIA));
    }
 
    public static void main(String[] args) {
        System.out.println("Enter maxValue: ");
        Scanner maxValue = new Scanner(System.in);
 
        double m = maxValue.nextDouble();
 
        System.out.println();
        System.out.println("isExclusive " + "" + "yearofProduction " + "" + "levelofEquipment " + "      " + "id" + "        " + "value ");
        printCarsToValueAndLevelOfEquipment(maxValue);
 
        System.out.println("Enter levelOfEquipment: ");
        Scanner levelOfEquipment = new Scanner(System.in);
 
        int l = levelOfEquipment.nextInt();
 
        System.out.println();
        System.out.println("isExclusive " + "" + "yearofProduction " + "" + "levelofEquipment " + "      " + "id" + "        " + "value ");
        printCarsToValueAndLevelOfEquipment(levelOfEquipment);
 
    }
}

package myPackage.exam.colections;
 
 
public class Car implements Comparable<Car> {
    boolean isExclusive;
    int yearOfProduction;
    int levelOfEquipment;
    int id;
    double value;
 
    public Car(boolean isExclusive, int yearOfProduction, int levelOfEquipment, int id, double value) {
        this.isExclusive = isExclusive;
        this.yearOfProduction = yearOfProduction;
        this.levelOfEquipment = levelOfEquipment;
        this.id = id;
        this.value = value;
    }
 
    public boolean getExclusive() {
        return this.isExclusive;
    }
 
    public Integer getYear() {
        return this.yearOfProduction;
    }
 
    public Integer getLevel() {
        return this.levelOfEquipment;
    }
 
    public Integer getId() {
        return this.id;
    }
 
    public double getValue() {
        return this.value;
    }
 
    public int compareTo(Car o) {
        return 0;
    }
 
    public String toString() {
        return this.isExclusive + "             " + this.yearOfProduction + "               " + this.levelOfEquipment + "               " + this.id + "         " + this.value;
    }
 
}

Error:

java: incompatible types: double cannot be converted to boolean