CODEWITHSUNDEEP
javaandroid
user3447262
user3447262

Reputation: 3

How to check if a variable of an object in an ArrayList is equal to any of the same variables of the other objects in the ArrayList

I have an ArrayList of the Class ZombieSprite in my GameView class which includes all my ZombieSprites. In my ZombieSprite class i have the method getDirection(). Now i dont want the ZombieSprites to collide. So need to check if the variable x of the object thezombiesprite id the ArrayList is equal to any other variable x of an object thezombiesprite in the ArrayList.

public class GameView extends SurfaceView {
  // not interesting 
  List<ZombieSprite> zombieSpriteList = new ArrayList<ZombieSprite>();
  // not interesting

public class ZombieSprite {
    private int x = 0;
private int y = 0;
  private void getDirection() {
    if (x < PlayerSprite.x) {
        x = x + xSpeed;
    }
    if (x > PlayerSprite.x) {
        x = x - xSpeed;
    }
    if (x == PlayerSprite.x) {
        x = x;
    }
    if (y < PlayerSprite.y) {
        y = y + ySpeed + backgroundspeed;
    }
    if (y > PlayerSprite.y) {
        y = y - ySpeed + backgroundspeed;
    }
    if (y == PlayerSprite.y) {
        y = y + backgroundspeed;
    }

}

I tried it with including following code into the getDireciton() method and added the ArrayList zombieSpriteList into the ZombieSprite class, too.

            theGameView.getZombieSpriteList();
    theGameView.zombieSpriteList = zombieSpriteList;
    for (ZombieSprite thezombiesprite : zombieSpriteList) {

    }

Upvotes: 0

Views: 631

Answers (2)

Edwin Torres
Edwin Torres

Reputation: 2854

I think you need to check both x and y. What you can do is create a two-dimensional array that represents your N x M grid. The indices of the array are the x , y coordinates. So when a zombie moves, check if grid[x,y] is occupied. If it is not, mark that space and remove the previous grid[x,y] value.

Upvotes: 1

tauitdnmd
tauitdnmd

Reputation: 368

You can override the method equal(Object obj) .

public boolean equals(Object o) {
    if(o instanceof ZombieSprite)
        return ((ZombieSprite)o).x == this.x;
    return super.equals(o);
}

Then if you want to check if a zoombiesprite exists in theGameView.zombieSpriteList or not ( by x value)

theGameView.zombieSpriteList.contains(...)

Upvotes: 2

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