done it :P took a little bit of smoke coming out my ears but its done import greenfoot.*; // (World, Actor, GreenfootImage, Greenfoot and MouseInfo) /** * Write a description of class invader here. * * @author (your name) * @version (a version number or a date) */ public class invader extends Actor { /** * Act - do whatever the invader wants to do. This method is called whenever * the 'Act' or 'Run' button gets pressed in the environment. */ int count =10; public void act() { // Add your action code here. setLocation(getX() -1, getY() ); Actor a = getOneIntersectingObject(bullet.class); if (a != null) { count = count -1; getWorld().removeObject(a); } if (count == 0) { getWorld().removeObject(a); getWorld().removeObject(this); return; } } }

Please show what code you have at this point (as far as trying to assign number of hits allowed per row of invaders). Use the 'code' link below the 'Post a reply' box to insert your code. You should probably show the Invader class from line 1 up to and including the constructor and the 'addedToWorld' method (if you have one); plus, your world class where you create and add the Invader objects into the world.

the code that i am using there is the actual invader code and how can i make my invaders slower than -1 so like -0.1 on the getX() -1 (doesnt allow doubles ) :(

Sorry, I was not initially up when I started my post. Still need the code mentioned in your subclass of World. Will deal with speed of invaders after resolving the HP issue.

i have sorted the HP issue with the code i posted but here is the world code

Alright, I did not understand that being the case in your last post (I was not sure what 'it' was referring to). Add another int field to your invader class to count act cycles. Then in your act method, if it is divisible by 10, have the invader move; then increment the counter:

how does this acts work i don't understand it 100%

If you do not want your invader to move 1 pixel every act method and you want it only to move 1 pixel every 10 act methods, then you need to count act cycles. This is what 'acts' whill hold -- the running count of act cycles. But we do not need it to run past 10, just need it to restart counting after it reaches 10 (that is what line 2 above does). The 'if' statement puts a condition on the movement code to execute only every 10th act (essentially, slowing down the invader). You can change the '10's in the two lines to any positive number as adjust the speed as wanted. The higher the number, longer the 'delay' between movements (or the slower the invader will move).

awesome thanks again for the help

ummm i don't think i am using it properly here is the code for invader