How to access a variable from a constructor of a different class in java?

Question

So I have 3 classes and I want to access one variable from two of them to get them summed up in the third one. Here is the code:

import java.util.*;

public class Car{
    String tip,marka;
    public double sborMestaCar = 0;
    double mesta, skorost;


public Car(String tip, String marka, double mesta, double skorost){
    Scanner sc = new Scanner(System.in);

    System.out.println("Vavedete tiput na kolata.");
    tip = sc.nextLine();

    System.out.println("Vavedete markata.");
    marka = sc.nextLine();

    System.out.println("Vavedete mestata.");
    mesta = sc.nextDouble();

    System.out.println("Vavedete max. skorostta.");
    skorost = sc.nextDouble();

    System.out.println("Suzdadenata kola e ot tip " + tip + ", markata e " + marka + ", ima " + mesta + " mesta i maksimalnata i skorost e " + skorost);

    sborMestaCar = sborMestaCar + mesta;
}
public Car(double sborMesta){
    sborMestaCar = sborMesta;

}

}

2nd one

import java.util.*;

public class Plane {
    String tip,marka;
    double mesta1k, mesta2k, skorost;
    public int sborMestaSam = 0;


public Plane( String tip, String marka, double mesta1k, double mesta2k, double skorost ){
    Scanner sc = new Scanner(System.in);


    System.out.println("Vavedete tiput na samoleta.");
    tip = sc.nextLine();

    System.out.println("Vavedete markata na samoleta.");
    marka = sc.nextLine();

    System.out.println("Vavedete mestata za purva klasa.");
    mesta1k = sc.nextDouble();

    System.out.println("Vavedete mestata za vtora klasa.");
    mesta2k = sc.nextDouble();

    System.out.println("Vavedete max. skorostta.");
    skorost = sc.nextDouble();

    System.out.println("Suzdadeniqt samolet e ot tip " + tip + ", markata e " + marka + ", ima " + mesta1k + " mesta v purva klasa, " + mesta2k +" mesta vuv vtora klasa" + " i maksimalnata i skorost e " + skorost);
}
    public Plane(double sborMesta){
        sborMestaSam = sborMesta;

}

}

And 3rd one.

import java.util.*;

public class TestPlane {
    public static void main(String[] args){

        String marka = "", tip = "";
        int mesta = 0, mesta1k = 0, mesta2k = 0, skorost = 0;
        int b = 1, c = 1;
        double sborMestaK = 0, sborMestaS = 0, obshtSbor = 0;



        Scanner sc = new Scanner(System.in);

        while(b == 1){
            Car car = new Car(tip, marka, mesta, skorost);
            System.out.println("Iskate li da suzdadete druga kola? 1 = Da 0 = Ne");
            b = sc.nextInt();
        }

        System.out.println("Vie zavurshihte suzdavaneto na kolite. Preminavane kum suzdavane na samoleti...");

        while(c == 1){  
            Plane plane = new Plane(tip, marka, mesta1k, mesta2k, skorost);
            System.out.println("Iskate li da suzdadete drug samolet? 1 = Da 0 = Ne");
            c = sc.nextInt();
        //  sborMesta = 
        }
        Car obshtiMestaK = new Car(sborMestaK);
        Plane obshtiMestaS = new Plane(sborMestaS);
        obshtSbor = obshtiMestaK.sborMestaCar + obshtiMestaS.sborMestaSam;
        System.out.println("Sbora ot mestata na vsi4ki sazdadeni prevozni sredstva e raven na " + obshtSbor);
    }

    }

You can look at the 3rd class at the end in the System.out.println part you can see that I have obshtSbor - the variable which is consisted from obshtiMestaK.sborMestaCar + obshtiMestaS.sborMestaSam. The program works BUT returns 0 as value for obshtSbor.

Answer 1

So first of all you are using wrong assignment, trying to change argument value to that of the field for both Car and Plane. Should rather be sborMestaCar = sborMesta and sborMestaSam = sborMesta.

Secondly, you are using 0 as an argument to both Car and Plane constructors double sborMestaK = 0, sborMestaS = 0, obshtSbor = 0; so 0+0=0. What did you expect to see?