Game of life comparison

new.js

function main(width = 50, height = 20, refreshRate = 250) {
  let life = generateRandomBoard(width, height);
  draw(life);
  setInterval(() => {
    life = nextGeneration(life);
    draw(life);
  }, refreshRate);
}

const states = {
  live: "x",
  dead: "-",
};

const nextGeneration = (board) =>
  board.map((row, ri) => {
    const prevRow = board[ri - 1] || [];
    const nextRow = board[ri + 1] || [];
    return row.map((cell, ci) => {
      const neighbours = [
        prevRow[ci - 1],
        prevRow[ci],
        prevRow[ci + 1],
        row[ci - 1],
        row[ci + 1],
        nextRow[ci - 1],
        nextRow[ci],
        nextRow[ci + 1],
      ];

      const live = neighbours
        .join("")
        .replace(new RegExp(states.dead, "g"), "").length;

      // Any live cell with two or three live neighbours survives.
      if (cell === states.live && (live === 2 || live === 3)) {
        return states.live;
      }
      // Any dead cell with three live neighbours becomes a live cell.
      if (cell === states.dead && live === 3) {
        return states.live;
      }
      // All other live cells die in the next generation. Similarly, all other dead cells stay dead.
      return states.dead;
    });
  });

function draw(board) {
  const border = `${(board[0] ?? []).map((_) => "-").join("")}`;
  console.clear();
  console.log(
    `/${border}\\\n${board
      .map((row) => `|${row.join("")}|`)
      .join("\n")}\n\\${border}/`
  );
}

const generateRandomBoard = (width = 0, height = 0) =>
  Array.from({ length: height }, (_, y) => {
    return Array.from({ length: width }, (_, x) => {
      return randomCell();
    });
  });

const randomCell = () => (Math.random() * 10 > 6 ? states.live : states.dead);

main();

old.js

function main(widht, height, refreshRate) {
  var w = widht || 50,
    h = height || 20,
    rr = refreshRate || 250;

  var life = randomLife(w, h);
  draw(life);
  setInterval(() => {
    life = generation(life);
    draw(life);
  }, rr);
}

var live = "x";
var dead = "-";

function generation(life) {
  var next = [];
  for (var r = 0; r < life.length; r++) {
    var row = life[r];
    next.push([]);
    for (var c = 0; c < row.length; c++) {
      var cell = row[c];
      var liveNeighbors = countLiveNeighbors(c, r, life);
      if (cell === live && (liveNeighbors === 2 || liveNeighbors === 3)) {
        // Any live cell with two or three live neighbours survives.
        next[r][c] = live;
      } else if (cell === dead && liveNeighbors === 3) {
        // Any dead cell with three live neighbours becomes a live cell.
        next[r][c] = live;
      } else {
        // All other live cells die in the next generation. Similarly, all other dead cells stay dead.
        next[r][c] = dead;
      }
    }
  }
  return next;
}

function draw(life) {
  var output = "/";
  for (var c = 0; c < life[0].length; c++) {
    output += "-";
  }
  output += "\\\n";
  for (var r = 0; r < life.length; r++) {
    var row = life[r];
    for (var c = 0; c < row.length; c++) {
      if (c === 0) {
        output += "|";
      }
      var cell = row[c];
      output += cell;
      if (c === row.length - 1) {
        output += "|";
      }
    }
    output += "\n";
  }
  output += "\\";
  for (var c = 0; c < life[0].length; c++) {
    output += "-";
  }
  output += "/";
  console.clear();
  console.log(output);
}

function countLiveNeighbors(c, r, life) {
  return (
    getCell(c - 1, r - 1, life) +
    getCell(c, r - 1, life) +
    getCell(c + 1, r - 1, life) +
    getCell(c - 1, r, life) +
    getCell(c, r, life) +
    getCell(c - 1, r + 1, life) +
    getCell(c, r + 1, life) +
    getCell(c + 1, r + 1, life)
  ).replace(new RegExp(dead, "g"), "").length;
}

function getCell(c, r, life) {
  return (life[r] || [])[c] || dead;
}

function randomCell() {
  return Math.random() * 10 > 6 ? live : dead;
}

function randomLife(width = 0, height = 0) {
  var out = [];
  for (let r = 0; r < height; r++) {
    out.push([]);
    for (let c = 0; c < width; c++) {
      out[r].push(randomCell());
    }
  }
  return out;
}

main();