con2

let num, w;
let cell = [];  //Declare the array
function setup() {
  createCanvas(400, 400);
  num = 3;
  for(let i = 0; i < num; i++){
    let arr = [];
    for(let j = 0; j < num; j++){
      arr.push(new Cell(i,j));
    }
    cell.push(arr);
  }
  w = width/num;
}
function draw() {
  background(220);
  for(let i = 0; i < num; i++){
    for(let j = 0; j < num; j++){
      cell[i][j].show();
    }
  }
}

class Cell{
  constructor(x,y){
    this.x = x;
    this.y = y;
    this.count = 0;
    if(random(2)>1){
      this.isAlive = true;
    } else {
      this.isAlive = false;
    }
  }

  show(){
    if(this.isAlive){
      fill(255);
    }  else {
      fill(0);
    }
    rect(this.x*w, this.y*w, w, w);
  }
}