Discussions

You should probably get the random numbers for the problem before the for loop where the user attempts to answer it.

All you need is an instance int field for the number of hits required to kill the actor. Lower its value each time the actor is hit. When the value is lowered to the value of zero, remove the actor. If the enemy is not removed when touching the actor, you will need to track the touching state to determine when the touch occurs (as opposed to knowing if it is currently touching or not). This is so that you are not be constantly decrementing the value of health while the same occurrence of the touch continues.

I forgot to mention, setting 'vSpeed' to zero should be done when found on ground (in the 'onGround' method); and for falling, use something like this: <Code Omitted>

The boolean is to track the state of the "e" key -- so you can detect when it is initially pressed or released: <Code Omitted>

Later, you may end up improving the code even more. To see my way of creating a jump-n-run type movement, check out my Jump and Run Demo w/Moving Platform scenario.

think you very much!l have solved it.

If you use a the current version of Greenfoot, you can just change the method names to be able to use them in the Actor class: canSee → isTouching eat → removeTouching You can also find the API online: http://www.greenfoot.org/files/javadoc/

You could use a boolean field to decide which method to execute. <Code Omitted>

Okay, nevermind. The issue was I was calling this method during the preparing phase. The spaceship was already made, but I found a workaround.

You are removing the actor from the world before calling the 'SpawnTile' method (which requires the actor be in a world because you cannot call a method, like 'addObject' on 'getWorld' when 'getWorld' returns a 'null' value). Remove the act after calling 'SpawnTile', which can be simplified to this: <Code Omitted>

On the menubar, try 'Edit>New Class...'. Just change the word 'class' to 'interface' in the editor. Of course, you could create any type class (World subclass or Actor subclass, for examples) and clear it of all initial code and start by adding the following to the class: <Code Omitted>The greenfoot application should be able to sort out where the

If not removing the touched actor, an instance field to track the touching state is needed: <Code Omitted>Adding the tracking field allows you to detect when the state changes instead of just knowing the current state. Of course, your touched actor is not of the Scorer class and you should adjust the name to suit your class.

The 'prepare' method in the Level_2 class does not add the counter into the world.

You will need to supply the code related to the issue -- particularly the code of the player.

The last phrase says it all. Use it with an int timer or a boolean that tracks the state of the key. A timer will allow continuous regulated shooting while the key is held down. A boolean that tracks the state of the field can be used to only shoot when the key changes state (from up to down or from down to up).