#Greenfoot random code

Now picking the square for a coin is straightforward: Pair where = validPairs.get(getRandomNumber(0, validPairs.size() - 1)) ĪddObject(character, where.getX(), where. ValidPairs.remove(new Pair(duckDudeX, duckDudeY)) The Random.nextInt(int) JavaDoc says (in part) Returns a pseudorandom, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive). int rand -15 + new Random().nextInt(31) is the range -15 to 15. My version uses a list of valid square coordinates, so it requires a bit of initialization: List validPairs = new ArrayList(49) First, try to only create the Random instance once, but for an example. This is also the basic idea in a couple of the other answers. The other option is you exclude the forbidden square already when picking the square. What is not so satisfactory about it is that even though it will eventually terminate, we know no upper bound on the number of iterations it will take. And again until you get a different position: int x If you hit the duckDude position, you pick again. The simple way is, you pick the two random integers. Methods, how can I make it generate a random location that excludes 5 and 5 together? So, is there a way I can generate these random ints, using the public int getRandomNumber(int start,int end) As you have probably seen, this poses quite a problem: if theDuckDude and a coin actor are generated on the same square, the game won't work properly:

#Greenfoot random code

Obviously, this code shows that when my theDuckDude character touches the coin actor, the coin is removed. The maximum number for the x and y come from the getWidth() and getHeight() methods. Good ideas I was always going to get round to rewriting the levels properly so they werent just random, but I did it that way. Here is a snippet of the code from my theDuckDude character: Actor actor = getOneIntersectingObject(coin.class) The next two lines generate random x and y coordinates for the new fly using the Greenfoot.getRandomNumber() function. So, as you can see, the three coins and duck character will appear on the screen in random locations. MainCharacter theDuckDude = new MainCharacter () ĪddObject(coin1, getRandomNumber(1, 7), getRandomNumber(1, 7)) ĪddObject(coin2, getRandomNumber(1, 7), getRandomNumber(1, 7)) ĪddObject(coin3, getRandomNumber(1, 7), getRandomNumber(1, 7)) Create a new world with 600x400 cells with a cell size of 1x1 pixels. * Constructor for objects of class FirstLevel. Public int getRandomNumber(int start,int end) I have written this code: public class FirstLevel extends World I've been working on a project in Greenfoot, with Java, where the main character is on a 7x7 screen with 3 coins. Int normal = Greenfoot.getRandomNumber(end-start+1) By pressing the number keys on the keyboard, the cards can be flipped. EDIT: This is a different question to How do I generate random integers within a specific range in Java? because I requested the solution uses the methods public int getRandomNumber(int start,int end) xs, assigned randomly every run of the program.