Java accessing class variables?

Question

Below is my program artificial bug. How would i be able to access the coorordinates from main which the user has set, and assign them to an array which is set in the MyClass class, thanks in advance:)

//imports
import java.util.Scanner;
import java.util.Random;


public class main {

    public static void main(String[] args) {

        Scanner reader = new Scanner(System.in);
        ABug[] BugObj = new ABug[4]; //Creating object BugObj of class ABug
        int loop = 4;
        int i = 0;
        int cycles;
        MyClass worldnew = new MyClass();



        System.out.println("Please enter the number of cycles you wish to run:");   
        cycles = reader.nextInt(); //getting the amount of cycles to be run
        System.out.print("____Current World____\n\n");
        worldnew.printWorld(); //calling method to print out world

        System.out.println("____Key____\n_F_ - Food\n_O_ - Object\n_ _ - Space\nSymbol - Bug");


        do{

            BugObj[i] = new ABug();  //creating instance


            System.out.print("Please enter the symbol which you wish to represent the bug:");
            BugObj[i].symbol = reader.next();
            System.out.print("Please enter the name of the bug:");
            BugObj[i].name = reader.next(); 
            System.out.println("Please enter the species of the bug:");   
            BugObj[i].species = reader.next(); 
            System.out.println("Please enter the horizontal position of the bug:");   
            BugObj[i].horpos = reader.nextInt();
            System.out.println("Please enter the vertical postion of the bug:");   
            BugObj[i].vertpos = reader.nextInt();   


            System.out.println("_______________ Bug " +(+i+1) + " _______________\n" );
            System.out.println("Symbol: " + BugObj[i].symbol);     //Printing bug information out
            System.out.println("Name: " + BugObj[i].name);           
            System.out.println("Species: " + BugObj[i].species);
            System.out.println("Horizontal Position: " + BugObj[i].horpos);
            System.out.println("Vertical Postion: " + BugObj[i].vertpos + "\n\n");
            move(BugObj[i]);


            i++;
            System.out.println("Would you like to enter another bug? \n 0-No,  1-Yes\n");
            loop = reader.nextInt();
        }while(loop == 1);
    }


    public static void move(ABug bug){
        Scanner reader = new Scanner(System.in);
        System.out.println("Would you like this bug to move?\n 0-No,  1-Yes\n");
        if (reader.nextInt() == 0)
        {
            System.exit(0);
        }



        //get corordinate of bug
        //set map[coor] = symbol
        //print out map


        int r = (int) (Math.random() * (2- -2)) + -2;
        int originalHorpos = bug.horpos;
        int originalVertpos = bug.vertpos;
        bug.horpos = originalHorpos + r;
        bug.vertpos = originalVertpos + r;


        System.out.println("New Horizontal Position: " +bug.horpos );
        System.out.println("New Vertical Postion: " +bug.vertpos);

    }

}

enum Item {
    OBJECT ('O'),FOOD ('F'), SPACE (' ');

    private final char symbol;
    Item(char symbol) {
        this.symbol = symbol;
    }
    char getSymbol() { return symbol; }
}

class MyClass {
    Item[][] map = new Item[15][25];
    public void printWorld() {

        int v, h; //v - vert, h - hor

        for (v=1; v<=15; ++v)
        {
            for (h=1; h<=25; ++h)
            {

                final Item[] items = {Item.OBJECT, Item.FOOD, Item.SPACE, Item.SPACE, Item.SPACE, Item.SPACE, Item.SPACE, Item.SPACE};
                Random random = new Random();
                int selection = random.nextInt(items.length);
                map[v-1][h-1] = items[selection];
                System.out.print(map[v-1][h-1].getSymbol() + "_"); 


            }
            System.out.printf("\n");
        } 
    }
}

class ABug {                 //ABug class
    int horpos, vertpos, energy, id;
    String species, name, symbol;

}

edit

package buglife;



//imports
import java.util.Scanner;
import java.util.Random;


public class main {

 public static void main(String[] args) {

  Scanner reader = new Scanner(System.in);
  ABug[] BugObj = new ABug[4]; //Creating object BugObj of class ABug
  int loop = 4;
  int i = 0;
  int cycles;
  MyClass worldnew = new MyClass();



  System.out.println("Please enter the number of cycles you wish to run:");   
  cycles = reader.nextInt(); //getting the amount of cycles to be run
  System.out.print("____Current World____\n\n");
  worldnew.printWorld(); //calling method to print out world

  System.out.println("____Key____\n_F_ - Food\n_O_ - Object\n_ _ - Space\nSymbol - Bug");


  do{

   BugObj[i] = new ABug();  //creating instance


   System.out.print("Please enter the symbol which you wish to represent the bug:");
   BugObj[i].symbol = reader.next();
   System.out.print("Please enter the name of the bug:");
   BugObj[i].name = reader.next(); 
   System.out.println("Please enter the species of the bug:");   
   BugObj[i].species = reader.next(); 
   System.out.println("Please enter the horizontal position of the bug:");   
   BugObj[i].horpos = reader.nextInt();
   System.out.println("Please enter the vertical postion of the bug:");   
   BugObj[i].vertpos = reader.nextInt(); 


   System.out.println("_______________ Bug " +(+i+1) + " _______________\n" );
   System.out.println("Symbol: " + BugObj[i].symbol);     //Printing bug information out
   System.out.println("Name: " + BugObj[i].name);           
   System.out.println("Species: " + BugObj[i].species);
   System.out.println("Horizontal Position: " + BugObj[i].horpos);
   System.out.println("Vertical Postion: " + BugObj[i].vertpos + "\n\n");
   move(BugObj[i], worldnew);


   i++;
   System.out.println("Would you like to enter another bug? \n 0-No,  1-Yes\n");
   loop = reader.nextInt();
  }while(loop == 1);
 }


 public static void move(ABug bug, MyClass wolrdnew){
  Scanner reader = new Scanner(System.in);
  System.out.println("Would you like this bug to move?\n 0-No,  1-Yes\n");
  if (reader.nextInt() == 0)
  {
   System.exit(0);
  }

  int x = bug.horpos;
  int y = bug.vertpos;


  worldnew.setMap(x,y,bug.symbol());
  worldnew.printWorld();

  //get corordinate of bug
  //set map[coor] = symbol
  //print out map


  int r = (int) (Math.random() * (2- -2)) + -2;
  int originalHorpos = bug.horpos;
  int originalVertpos = bug.vertpos;
  bug.horpos = originalHorpos + r;
  bug.vertpos = originalVertpos + r;


  //bug.horpos += r; 
  //bug.vertpos += r;

  System.out.println("New Horizontal Position: " +bug.horpos );
  System.out.println("New Vertical Postion: " +bug.vertpos);

 }
}

//public void smellFood (Direction d){
// int MaxSensingDist = 2;
//}

//public void getRandomDirectionToMove (Direction d){
//
//}

//public void getDirectionOfFood (){

//}


enum Item {
 OBJECT ('O'),FOOD ('F'), SPACE (' ');

 private final char symbol;
 Item(char symbol) {
  this.symbol = symbol;
 }
 char getSymbol() { return symbol; }
}
class MyClass {

 public void setMap(int x, int y, Item symbol)
 {
  this.map[x][y] = symbol;
 }
 Item[][] map = new Item[15][25];
 public void printWorld() {

  int v, h; //v - vert, h - hor

  for (v=1; v<=15; ++v)
  {
   for (h=1; h<=25; ++h)
   {

    //map[0][0] = Item.TREE;
    //map[0][1] = Item.FOOD;
    //System.out.print(map[0][0].getSymbol());
    //System.out.print(map[0][1].getSymbol());

    //final String[] items = {"F", "O", ". ", ". ", ". ", ". ", ". ", ". "};
    //Random random = new Random();
    //int index = random.nextInt(items.length);
    //System.out.printf(items[index] + "\t");  

    final Item[] items = {Item.OBJECT, Item.FOOD, Item.SPACE, Item.SPACE, Item.SPACE, Item.SPACE, Item.SPACE, Item.SPACE};
    Random random = new Random();
    int selection = random.nextInt(items.length);
    map[v-1][h-1] = items[selection];
    System.out.print(map[v-1][h-1].getSymbol() + "_"); 


   }
   System.out.printf("\n");
  } 
 }
}
class ABug {                 //ABug class
 int horpos, vertpos, energy, id;
 String species, name, symbol;

}

Check [How do getters and setters work?](http://stackoverflow.com/questions/2036970/how-do-getters-and-setters-work) — sam, Nov 04 '15 at 18:02

AbtPst · Answer 1 · 2015-11-04T20:25:24.403

1

how about just

int x = bug.get(horpos);
int y = bug.get(vertpos);

worldnew.setMap(x,y,bug.getSymbol());

worldnew.printWorld();

and in MyClass, add a new method like

void setMap(int x, int y, String symbol)
{
    this.map[x][y] = symbol;
}

you might need to make some changes to suit your code, but the basic idea remains the same

Edit

you will also need to change the

move(BugObj[i]);

to

move(BugObj[i],worldnew);

and change the definition of your move function as

public static void move(ABug bug, MyClass worldnew)

edited Nov 04 '15 at 20:25

answered Nov 04 '15 at 18:18

AbtPst

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Thanks, i have added it to my code and changed it around, however when i insert the 'worldnew.setMap(x,y,bug.symbol()); worldnew.printWorld();' into the move method, Its saying that 'worldnew is not resolved. – Logic Nov 04 '15 at 19:14
thats because worldnew does not exist in that function. please see the edit to my answer – AbtPst Nov 04 '15 at 20:25
Thanks, i have added that in, however its still not recognising the worldnew.setMap. Is there a way to allow access? – Logic Nov 04 '15 at 20:50
you have to create the setMap function in MyClass – AbtPst Nov 04 '15 at 20:54
worldnew.setMap(x,y,bug.symbol()); worldnew.printWorld(); worldnew cannot be resolved, this is the only error i get, not sure whats wrong as bug.horpos was working fine. – Logic Nov 04 '15 at 20:54
did you change the definition of your move function as public static void move(ABug bug, MyClass worldnew) ? – AbtPst Nov 04 '15 at 20:56
Yes, code shown above, might be formatting issue or something small that im overlooking. – Logic Nov 04 '15 at 21:02
yeah because your bug.Symbol is a string but your method requires an Item – AbtPst Nov 04 '15 at 21:08
you need to convert the bug.Symbol to Item – AbtPst Nov 04 '15 at 21:09
also, the method needs to be bug.getSymbol(). you have bug.Symbol(), which is incorrect – AbtPst Nov 04 '15 at 21:10
just try to get the symbol the same you get the horpos and vertpos, so like bug.symbol – AbtPst Nov 04 '15 at 21:12
without the paranthesis – AbtPst Nov 04 '15 at 21:12

Java accessing class variables?

1 Answers1