One projectile colliding with two objects - Array index out of bounds -1

Newbie & Debugging Questions
#1

I have a character in a 2D world that shots a projectile. I have a particular case where if there are 2+ objects overlapping, and I shoot them with my character, I get an array index out of bounds exception when I attempt to remove the projectile I shot from a local Array.


    private Iterator<Enemy> enemyIter;
    private Iterator<Bullets> bulletIter;
    private Array<Enemy> enemyList = new Array<Enemy>();
    private Array<Bullets> bulletsList = new Array<Bullets>();



        bulletIter = bulletsList.iterator();            // If bullet touches enemy, remove enemy from enemyList
        
        while(bulletIter.hasNext()) {
            bullets = bulletIter.next();
            enemyIter = enemyList.iterator();
            
            while(enemyIter.hasNext()) {
                enemy = enemyIter.next();

                if (enemy.getBounds().overlaps(bullets.getBounds())) {
                    enemyIter.remove();
                    bulletIter.remove();
                }
            }
        }

The issue happens on the “bulletIter.remove();” near the bottom.

Its an interesting problem because I know it only happens when I have two enemies that are overlapping each other, and I try to shoot them. I assume that the bullet overlaps multiple enemies, and therefore there is an exception when trying to remove the same bullet twice. I assumed that this wouldn’t happen for a single threaded application, so I’m very confused on how to solve this.

Any advice would be greatly appreciated!

#2

Since you have nested the enemy while loop inside the bullet while, looks like there needs to be a way to go to the next bullet if the current one has been removed due to a collision. In this case I think using break; would work.

#3

Adding break after the bullet removal work perfectly!

Thank you so much – I’ve been staring at the screen for too long. Very elegant solution.