Processing - Array index out of bounds error

Question

I'm trying to use an array of objects to have barrels fall from the top of the screen to the bottom. (Like that old donkey kong game.) However, I can't seem to find a way to create more instances of the object than whatever the initial length of the array was. Anyone know a way to do this?

Here's the code:

Man Man;
Man background;
Man ladders;
PFont font1;
int time;
boolean run;
boolean newBarrel;
int barrelTotal;
Barrel[] barrel = new Barrel[100];
void setup() {
  newBarrel = false;
  run = true;
  barrelTotal = 1;
  time = millis();
  size(800, 800);
  Man = new Man();
  background = new Man();
  ladders = new Man();
  for (int i = 0; i < barrel.length; i++) {
    barrel[i] = new Barrel();
  }
}
void draw() {
  if (run == true) {
    for (int i = 0; i < barrel.length; i++) {
      if ((Man.bottom-10 >= barrel[i].top)&&(Man.bottom-10 <= barrel[i].bottom)&&(Man.Ladder == barrel[i].randomLadder)) {
        print("GAME OVER!");
        run = false;
      }
      if ((Man.top >= barrel[i].top)&&(Man.top <= barrel[i].bottom)&&(Man.Ladder == barrel[i].randomLadder)) {
        print("GAME OVER!");
        run = false;
      }
    }
  }
  if (run == true) {
    background.createBackground();
    Man.ladders();
    Man.movement();
    Man.createMan();
    //spawns a barrel every second
    if (millis()> time + 10) {
      newBarrel = false;
      print("     " + barrelTotal + "        ");
      time = time + 10;
      barrelTotal = barrelTotal+1;
      newBarrel = true;
    }
    for (int i = 0; i < barrelTotal; i++) {
      if (newBarrel == true) {
      }
      barrel[i].gravity();
      barrel[i].createBarrel();
    }
    //if(barrelTotal == 100){
    //for (int i = 0; i < 50; i++){
    // barrel[i] = "???";
    //}
    //}
  }
}

Kevin Hooke · Accepted Answer · 2021-12-20 16:18:12Z

1

Use an ArrayList instead of a native array. ArrayList will expand capacity as needed, whereas an array is fixed size and cannot be changed (you'd need to create a new larger array each time, which under the covers is what an ArrayList handles for you).

answered Dec 20, 2021 at 16:18

Kevin Hooke

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Comments

Rabbid76 · Accepted Answer · 2021-12-21 16:54:07Z

1

You can use ArrayList for this. You will change

// from
Barrel[] barrel = new Barrel[100]; // i suggest naming it to barrels instead of barrel
// to 
ArrayList<Barrel> barrel = new ArrayList<>(); 
// or better 
List<Barrel> barrel = new ArrayList<>();
// from 
 for (int i = 0; i < barrel.length; i++) {
    barrel[i] = new Barrel();
  }
// to
 for (int i = 0; i < barrel.length; i++) {
    barrel.add(new Barrel());
  }
// from
barrel[i].<some-method()/attribute>
// to
barrel.get(i).<some-method()/attribute>
// etc

I highly recommend this for getting started with lists https://docs.oracle.com/javase/tutorial/collections/interfaces/list.html

edited Dec 21, 2021 at 16:54

Rabbid76

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answered Dec 20, 2021 at 16:19

Abdullah Khaled

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