Create ArrayList based with object based on method parameter

Question

I have a Class with Balls.

In another class called CollectionBalls i have a collection of Balls (what a suprise)

The class CollectionBalls has a ArrayList of the type balls :

 ArrayList <Balls> myBalls;

What i want to do is when i create the object CollectionBalls is : set the ammount of balls in the parameter of the constructor.

like

public CollectionBalls(int amountOfBalls)
{
    myBalls = new ArrayList <Balls>();
    setAmountOfBalls(amountOfBalls);
}

public void setAmountOfBalls(int amountOBalls)
{
    for (int i = 0; i < amountOBalls;  i ++)
    {
        // Create a new ball
        Ball i = new Ball();
        // Add the ball to the collection of ball
        myBalls.add(i);
    }
}

but i cant create a new ball dynamicly with i.

How can i create the amount of object based on the parameter?

edit: i can rename i with something like testBall but testBall is one object then instead of 10 object like ball 1 ball 2 ball 3 right?

Name your Ball variable something other than i, which is already used as the for loop index. — Sotirios Delimanolis
– Sotirios Delimanolis, Commented Jan 7, 2014 at 20:06
the constructor for Ball must also not have any arguments or you would need to supply them (Overloading constructors is also a thing). — Fallenreaper
– Fallenreaper, Commented Jan 7, 2014 at 20:07
@SotiriosDelimanolis i can rename i with something like testBall but testBall is one object then instead of 10 object like ball 1 ball 2 ball 3 right? — Sven van den Boogaart
– Sven van den Boogaart, Commented Jan 7, 2014 at 20:09
What does it matter what the Ball variables are called? You can't dynamically name variables in Java. — Sotirios Delimanolis
– Sotirios Delimanolis, Commented Jan 7, 2014 at 20:09
Read this. An object does not have a name. A variable does. That name cannot be created dynamically. — Sotirios Delimanolis
– Sotirios Delimanolis, Commented Jan 7, 2014 at 20:13

Elliott Frisch · Accepted Answer · 2014-01-07 20:15:29Z

2

I see two issues

public void setAmountOfBalls(int amountOBalls)
{
  for (int i = 0; i < amountOBalls;  i++)
  {
    // Create a new ball
    // Ball i = new Ball(); // you have a plural class name, but were trying to 
                            // make it singular here and you already have an 
                            // integer variable called i.
    Balls ball = new Balls();
    // Add the ball to the collection of ball
    myBalls.add(ball);
  }
}

answered Jan 7, 2014 at 20:15

Elliott Frisch

202k20 gold badges166 silver badges265 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Sven van den Boogaart Over a year ago

thx i used balls for the example to make it easyer to understand have adjusted it

Sven van den Boogaart Over a year ago

it was possible with char name = 'a' name ++;

danihodovic · Accepted Answer · 2014-01-07 20:15:31Z

2

public CollectionBalls(int amountOfBalls)
{
    myBalls = new ArrayList <Balls>();
    setAmountOfBalls(amountOfBalls);
}

public void setAmountOfBalls(int amountOBalls)
{
    for (int i = 0; i < amountOf**Registers**;  i ++)

        // Add the ball to the collection of ball
        myBalls.add(new Balls());
    }
}

answered Jan 7, 2014 at 20:15

danihodovic

1,2744 gold badges19 silver badges30 bronze badges

Collectives™ on Stack Overflow

Create ArrayList based with object based on method parameter

2 Answers 2

2 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related