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Why is my p5 javascript game of life not working?

I watched a coding train video about the game of life and i tried making a program but it doesn't work. It just generates random squares on the screen as a first image (the starting position) and then just generates another frame with the positive squares (white) disappearing and that's it. Only 2 frames. And it doesn't show an error. Can someone explain why?

function make2D(x, y) {
  let arr = new Array(x);
  for (let i = 0; i < x; i++) {
    arr[i] = new Array(y);
  }
  return arr;
}

let grid;
let col;
let row;
let resolution = 20;

function setup() {
  createCanvas(500, 500);
  col = width / resolution;
  row = height / resolution;
  grid = make2D(col, row);
  for (let i = 0; i < col; i++) {
    for (let j = 0; j < row; j++) {
      grid[i][j] = floor(random(2));
    }
  }
}

function draw() {
  frameRate(1);
  background(0);
  //drawing
  for (let i = 0; i < col; i++) {
    for (let j = 0; j < row; j++) {
      let x = i * resolution;
      let y = j * resolution;
      if (grid[i][j]) {
        fill(255);
      } else {
        fill(0);
      }
      rect(x, y, resolution, resolution);
    }
  }
  //processing
  let next = make2D(col, row);
  for (let i = 0; i < col; i++) {
    for (let j = 0; j < row; j++) {
      let nb = calculatePosition(grid, i, j);
      //fill(255,0,0);
      //text(grid[i][j],i*resolution+6,j*resolution+15);
      if (grid[i][j] == 0 && nb == 3) {
        next[i][j] == 1;
      } else if (grid[i][j] == 1 && (nb > 3 || nb < 2)) {
        next[i][j] == 0;
      } else {
        next[i][j] = grid[i][j];
      }
    }
  }
  grid = next;
}

function calculatePosition(grid, x, y) {
  let sum = 0;
  for (let i = -1; i < 2; i++) {
    for (let j = -1; j < 2; j++) {
      let cols = (x + i + col) % col;
      let rows = (y + j + row) % row;
      sum += grid[cols][rows];
    }
  }
  sum -= grid[x][y];
  console.log(sum);
  return sum;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.4.1/p5.js"></script>

about 4 years ago · Juan Pablo Isaza
1 answers
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0

You accidentally are using equality (==) instead of assignment (=) here

if (grid[i][j] == 0 && nb == 3) {
  next[i][j] == 1;
} else if (grid[i][j] == 1 && (nb > 3 || nb < 2)) {
  next[i][j] == 0;
} else {
  next[i][j] = grid[i][j];
}

You should also move your frameRate call to setup().

about 4 years ago · Juan Pablo Isaza Report
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