How to sporn random

To spawn an actor you need to use the addObject method. To generate a random number you can use Greenfoot.getRandomNumber(int). So of you want an object to spawn anywhere in your world you can use this code:

You need to add this code somewhere in your world class. I think in the act method would be best. (With an if-condition because otherwhise there will be a new object every act). But you can also past this code in an actor subclass (also in the act method). But then you have to change it like this:

the code : public void act() { if (!getWorld().getObjectsAt(getX() -1, getY() -1, Walter.class).isEmpty()) { getWorld().addObject(new Walter(), Greenfoot.getRandomNumber(getWorld().getWidth()), Greenfoot.getRandomNumber(getWorld().getHeight())); }}

I think you should use a different if clause. This if clause means that there should only spawn new objects if there is already an object at the coordinate x-1, y-1 of your actor. When do you want a new actor to spawn in the world? E.g. you could spawn a new actor if there are no more in the world:

i want a new actor sporn if i click act ore run so in the end it should sporn anywhere on the map and after 10 second it should spown at an ather place! but i thought i can do the time thing after the spown thing is ready

To just spawn new objects randomly you can use the code I gave you before without the if clause. To let the actors spawn after a certain time you need to add a counter. E.g. like this:

and the line done at the buttom said "method act() is already defined in class walter what schould i do ? i taked that code from your message but they get more and more but the first dont disapper so it is a 2. problem i have code : addObject(new YourClassName(), Greenfoot.getRandomNumber(getWidth()), Greenfoot.getRandomNumber(getHeight()));

The following is if you only have one Walter object in the world at a time: