Problem on multiple creation

Hi, i am new in JAVA and i have the following question.

I have a class with name 'box' and a class with name 'ball'.

I want, for example, to create 3 boxes consisting of 5 balls each.

I have 2 questions, yet :

(1) is the code i provide below correct ?

(2) if yes, then how can i call the function boxprint() from the first, second and third box ? (i dont want the b.boxprint(), but something

like b[0].boxprint() for the 1st box, b[1].boxprint() for the 2nd box and b[2].boxprint() for the 3rd box)


i provide below what i have tried so far:

Code:

---

import java.util.Vector;

public class Myprogram{
  protected int numboxes;
  protected int numballs;
 
  public Myprogram(int numboxes, int numballs){
      this.numboxes = numboxes;
          this.numballs = numballs;
  } 

  public void creation(){
    Box b = new Box(numboxes,numballs);
        b.boxprint(); // i want something like b[0].boxprint();
        //more code here
       
  }

  public static void main(String[] argv ){
      int numboxes = 3;
          int numballs = 5;
         
          Myprogram m = new Myprogram(numboxes, numballs);
          m.creation();
  }
}

---

Code:

---

import java.util.Vector;

public class Box{
  protected int numboxes;
  protected int numballs;
  protected Vector<Ball> balls;
 
  public Box(int numboxes, int numballs){
      this.numboxes = numboxes;
          this.numboxes = numballs;
          balls = new Vector<Ball>(numballs);
  } 
 
  public void boxprint(){
        System.out.println("Hello");
  }
}

---

Code:

---

import java.util.Vector;

public class Ball{
  protected int numballs;
 
  public Ball(int numballs){
      this.numballs = numballs;
  } 

}

---

ps i know the title is quite horrible.

Thanks.

Well, you've got Vector imported, so let's use it.

Code:

---

balls = new Vector<Ball>(numballs);  // this is correct, BUT does not create the Ball objects... this initializes a Vector with capacity set to numballs

---

The capacity of your Vector can increase, but this is good. (Vector by default doubles in size if you just use .add(Object) to implicitly increase the capacity.)

Here's a VERY simple Vector example:

Code:

---

        public static void main(String[] args){
                Vector<String> vs = new Vector<String>(4);  // Create a Vector with initial capacity of 4
                for(int i = 0; i < 4; i++){                              // Add 4 String objects to the Vector
                        vs.add("New String " + i);
                }
               
                for(int i = 0; i < vs.size(); i++){                  // This checks .size() on the Vector to determine how many Strings are in it.  This can be larger
                                                                            // than the _initial_ capacity. (but not the _current_ capacity)
                        System.out.println(vs.get(i));            // the .get(i) gets the Object at index i to act on it... in this case, prints it.
                }       
        }

---

sorry but i still cant understand.

if i want to call the boxprint() function from the second box or the third box in Myprogram class how will i do that ?

i was considering something like b[1].boxprint() for the second box or b[2].boxprint() for the trird box but it doesnt work.

it works only with b.boxprint(); but i cant understand this call in which box refers to ? number one, two or three box ?

i want actually the Box b = new Box(numboxes,numballs); the b to be a vector. i probably need something like vector of objects any idea ?

probably in the class Myprogram should i have : Vector<Box> b = new Vector<Box>(numboxes,numballs);

is that correct or not ? if yes then how to write b[0].boxprint() ??

i ll re-write my question to be more specific.

My target is to create 3 Box, and each Box to consist of 5 Balls.

I changed the code :

Code:

---

import java.util.Vector;

public class Myprogram{
  protected int numboxes;
  protected int numballs;
 
  public Myprogram(int numboxes, int numballs){
      this.numboxes = numboxes;
          this.numballs = numballs;
  }

  public void creation(int numboxes){
    Box b = new Box(numballs);
        Box c = new Box(numballs);
        Box d = new Box(numballs);
    //b = new Vector<Box>(numboxes,numballs);
        //b.boxprint(); // i want something like b[0].boxprint();  <---- SOS
        //more code here
  }

  public static void main(String[] argv ){
      int numboxes = 3;
          int numballs = 5;
         
          Myprogram m = new Myprogram(numboxes, numballs);
          m.creation(numboxes);
  }
}

---

Code:

---

import java.util.Vector;

public class Box{
  protected int numboxes;
  protected int numballs;
  protected Vector<Ball> balls;
 
  public Box(int numballs){
          this.numballs = numballs;
          balls = new Vector<Ball>(numballs);
  }
 
  public void boxprint(){
        System.out.println("Hello");
  }
}

---

Code:

---

import java.util.Vector;

public class Ball{
  protected int numballs;
 
  public Ball(int numballs){
      this.numballs = numballs;
  }

}

---

my question is that in class Myprogram in creation() function i want to change this part of code:

Code:

---

    Box b = new Box(numballs);
        Box c = new Box(numballs);
        Box d = new Box(numballs);

---

in one, in a vector. Something like Box b[] = new Box(numballs); how to make that change any idea ?