That causes the game to crash the when the projectile is added rather than when it is removed. :/

Edit: I switched using straight up Arrays and Longor's method and now it works! Using an Array also drastically increased performance, now my tick timer is all messed up. Thanks to everyone who helped!

Originally the remove was being called from inside the projectiles instance, but then I changed it using the flag method suggest by Agro. That didn't work either. The two instances in which the projectile is removed from the screen is when it leaves the viewing screen and when it hits the player or the AI (depending on who originally shot it). The collision detection is in the loop that I showed in the original post. I'm using to remove the projectile.

The concurrent modification exception still happens. 

I'm making a game kind of like Super Smash Bros. One of the attacks available to the player is a projectile fireball. All the fireball animation and collision is working perfectly, but whenever the code goes to remove a projectile from the screen, I get the following exception:

I'm using the following code for looping and removing:


Currently I'm using an ArrayList to hold all the projectile data. Would it help if I used a different type of array or made a flag in the projectile class that indicated that the projectile should no longer be updated/drawn?

Thanks for the help!

To elaborate, I want to draw images into a JFrame or JPanel.

Hello!
I have everything about my game down except graphics. So I would like to know an effective way to implement them.
I don't want you use anything fancy like lwjgl so please just natural to Java.

Thanks,
Red_dino