Size cannot be used here

hello i am creating a little game and everything was ok before an error appeared:

Could not run the sketch:
size cannot be used here.

here is my code (there is 4 authers classes):

boolean keys[];

int vaisseau_x = 10;
int vaisseau_y = 10;
int vaisseau_width = 50;
int vaisseau_height = 50;
int vaisseau_vitesse = 10;
int vaisseau_munitions = 1000;
int vaisseau_munitions_restantes = vaisseau_munitions + 1;
PImage vaisseau_image;

boolean tir_ouvert = false;

int assaillant_width = 30;
int assaillant_height = 30;
int assaillant_nombre = 100;
PImage assaillant_image;

int powerup_width = 20;
int powerup_height = 20;
int powerup_nombre = 20;
PImage powerup_image;

Assaillant[] assaillants = new Assaillant[assaillant_nombre];
Tir[] tir = new Tir[vaisseau_munitions];
Vaisseau[] vaisseau = new Vaisseau[1];
Powerup[] powerup = new Powerup[powerup_nombre];
void setup(){
  size(1024,768);
  frameRate(60);
  keys = new boolean[3];
  
  for(int i = 0; i < assaillants.length; i++) assaillants[i] = new Assaillant(ceil(random(width, width + 20000)), ceil(random(height - assaillant_height)), 2, ceil(random(30, 255)), assaillant_image);
    for(int i = 0; i < powerup.length; i++) powerup[i] = new Powerup(ceil(random(width, width + 20000)), ceil(random(height - powerup_height)), 5, powerup_image);
  vaisseau[0] = new Vaisseau(vaisseau_x, vaisseau_y, vaisseau_vitesse, vaisseau_image);
  
}

void draw(){
  background(255);
  
  for(int i = 0; i < assaillants.length; i++){
    assaillants[i].affichage();
    assaillants[i].deplacement();
  }
  
  if(tir_ouvert){
    for(int i = 0; i <= vaisseau_munitions - vaisseau_munitions_restantes; i++){
      tir[i].affichage();
      tir[i].deplacement();
    }
  }
  for(int i = 0; i < powerup.length; i++){
    powerup[i].affichage();
    powerup[i].deplacement();
  }
  vaisseau[0].affichage();
  deplacement();
  bordures();
}

void keyPressed(){
  if(key == 'e' || key == 'E') keys[0] = true;
  if(key == 'c' || key == 'C') keys[1] = true;  
  if(key == ' ') keys[2] = true;
}

void keyReleased(){
  if(key == 'e' || key == 'E') keys[0] = false;
  if(key == 'c' || key == 'C') keys[1] = false;
  if(key == ' ') keys[2] = false;
}

void deplacement(){
  if(keys[0] == true) vaisseau[0].pos_y -= vaisseau_vitesse;
  if(keys[1] == true) vaisseau[0].pos_y += vaisseau_vitesse;
  if(keys[2] == true) tirer();
}

void bordures(){
  if(vaisseau_y < 0) vaisseau_y = 0;
  if(vaisseau_y + vaisseau_height > height) vaisseau_y = height - vaisseau_height;
}

void tirer(){
  tir[vaisseau_munitions - vaisseau_munitions_restantes + 1] = new Tir(vaisseau[0].pos_y, 10);
  vaisseau_munitions_restantes -= 1;
  
  tir_ouvert = true;
  keys[2] = false;
}

ty a lot

Hey @yonjukyu. It seems that you have forgotten to post the other classes as well. Please post them here too.

Few tips for ya though: :blush:
[1] Use Ctrl + T to autoFormat your code so it is more readable. [Also, Edit > Auto Format]
[2] Use grave accent like this ` your code here ` so that it is formatted here on the forum better.

My speculation is that you used size (,) somewhere outside setup () {} in the other classes. In which case, you should know that size() function must be the first line of code inside setup().

Please refer to this reference to learn more.

To track down the problem, you can use Ctrl-F (Find) to search your sketch for “size”.