Greenfoot

Sammyy2323

2020/6/2

#

I need to take the random array number and turn it into that many balls added to the world. I have not defined any variable and I need help on how to do this for my final project. (Ex. if the array chooses the number 8, 8 balls would be placed in the world) public void CreateBalls() { int num = new int ; i num = Greenfoot.getRandomNumber(5-10); num = Greenfoot.getRandomNumber(5-10); num = Greenfoot.getRandomNumber(5-10); num = Greenfoot.getRandomNumber(5-10); for (int i= 0; i<num.length;i++) { } }

danpost

2020/6/2

#

You mean this?

for (int i=0; i<5+Greenfoot.getRandomNumber(6); i++)
{

}

danpost

2020/6/2

#

Oh, this is different:

Sammyy2323 wrote...

public void CreateBalls()
{
    int [] num = new int [4];
    i
    num [0] = Greenfoot.getRandomNumber(5-10); 
    num [1] = Greenfoot.getRandomNumber(5-10);
    num [2] = Greenfoot.getRandomNumber(5-10);
    num [3] = Greenfoot.getRandomNumber(5-10);
    for (int i= 0; i<num.length;i++) 
    {
       
    }
}

Where are you using the numbers in the array? As is, your loop will iterate exactly 4 times regardless of the random numbers chosen (because that is the length you set the array to on line 3). Why do you need 4 random values?

Sammyy2323

2020/6/2

#

i want to have 4 different color balls in the world and say is for a gold ball, the random number would place say 6 balls in the world. and for it is a different color and that will output say 7 balls in the world. Not sure on how to do this.

Sammyy2323

2020/6/2

#

the 0 in the array will stand for a gold ball and 1 in the array is for blue and so on

danpost

2020/6/2

#

Sammyy2323 wrote...

i want to have 4 different color balls in the world and say is for a gold ball, the random number would place say 6 balls in the world. and for it is a different color and that will output say 7 balls in the world. Not sure on how to do this.

Okay, makes a little more sense now. You will need a loop inside the loop you already have, counter based on random values:

for (int i=0; i<num.length; i++)
{
    for (int n=0; n<num[i]; n++)
    {

    }
}

Sammyy2323

2020/6/2

#

what would i put inside the inner loop? I understand that I need another loop inside of it but what would I put in it?

danpost

2020/6/2

#

Sammyy2323 wrote...

what would i put inside the inner loop? I understand that I need another loop inside of it but what would I put in it?

I presume you would be creating balls, the type of which would depend on i, and add them to the world.

Sammyy2323

2020/6/2

#

so would i put in the outer loop the random colors and in the inner loop I create that color ball?

danpost

2020/6/2

#

Sammyy2323 wrote...

so would i put in the outer loop the random colors and in the inner loop I create that color ball?

I would suggest the color be given by the Ball constructor. You would only need to pass its type value. At line 5 above:

Ball = new Ball(i);
// addObject line to follow

An example Ball class might be along these lines (incomplete):

public class Ball extends Actor
{
    private static final String[] COLORS = { "red", ... } // whatever the order is
    private int value;
    
    public Ball(int id)
    {
        value = id;
        setImage(new GreenfootImage(COLORS[value]+"-ball.png"));
    }
    
    public String getColor()
    {
        return COLORS[value];
    }
}

Sammyy2323

2020/6/2

#

ok so this will create the random color. Gotcha. But how would I make an int array with the random numbers and turn that into how many balls? Or did you already do that and I don't get this?

danpost

2020/6/2

#

Sammyy2323 wrote...

ok so this will create the random color. Gotcha. But how would I make an int array with the random numbers and turn that into how many balls? Or did you already do that and I don't get this?

I am not sure you get it or not. Your 13 line code post, modified with my 7 line code post with the line 5 insertion would be the end result for the CreateBalls method

Sammyy2323

2020/6/2

#

so i combine my first 13 line code and your 7 line code and add a little and the code will place a random amount of balls in the world and also a random color correct?

danpost

2020/6/2

#

Sammyy2323 wrote...

so i combine my first 13 line code and your 7 line code and add a little and the code will place a random amount of balls in the world and also a random color correct?

It will place 5 to 10 of each of 4 distinguishably different balls in the world. The Ball class, per my suggestion, would provide the proper color to each Ball instance depending on the value provided it.

Sammyy2323

2020/6/2

#

ok, and I would keep the CreateBalls method and then make the Ball method also? (sorry for asking questions, final project is due in like 2 days and I need to make sure this is correct)

Activity

About

Documentation

Download

Discuss

Scenarios

Help with arrays and for loop