js实现贪吃蛇游戏含注释

本文实例为大家分享了js实现贪吃蛇游戏的具体代码，供大家参考，具体内容如下

两个小时完成的，有点简陋。

直接看效果。打开调试面板，在resource面板，新建snippet

粘贴以下代码，右键snippet，run。

clearinterval(timer);
document.body.innerhtml = "";

//每秒移动多少格
let speed = 10;
let speedupmul = 3;

//是否能穿墙
let isthroughthewall = true;

//行数
let row = 40;
let headcolor = 'red';
let bodycolor = 'green';
let foodcolor = 'yellow';
let bordercolor = 'grey';


// 游戏全局变量
let hasfood = false;
//游戏状态
let gamestaus = 'start';
let hasaccelerate = false;

let maincontainer = document.createelement("div");
maincontainer.style.width = 20 * row + 1 + "px";
maincontainer.style.height = 20 * row + 1 + "px";
maincontainer.style.margin = "0 auto";
maincontainer.style.position = "relative";
maincontainer.style.border = "1px solid " + bordercolor;

document.body.appendchild(maincontainer);

for(let i = 0;i<row;i++){
 let margintop = 20 * i + "px";
 for(let j = 0;j<row;j++){
 let marginleft = j * 20 + "px";
 let tempdiv = document.createelement('div');
 tempdiv.style.width = "19px";
 tempdiv.style.height = "19px";
 tempdiv.style.margintop = margintop;
 tempdiv.style.marginleft = marginleft;
 tempdiv.style.border = "0.5px solid " + bordercolor;
 tempdiv.style.position = "absolute";
 tempdiv.id = j + "div" + i;
 maincontainer.appendchild(tempdiv);
 }
}

class cell{
 constructor(x, y, color){
 if(isthroughthewall){
  if(x < 0) x = row-1;
  if(x > row - 1) x = 0;
  if(y < 0) y = row - 1;
  if(y > row - 1) y = 0;
 }else{
  if(x < 0 || y < 0|| x > row - 1 || y > row - 1){
  clearinterval(timer);
  alert('游戏结束');
  return;
  }
 }
 this.x = x;
 this.y = y;
 this.color = color;
 let tempdiv = document.getelementbyid(x + 'div' + y);
 if(tempdiv) tempdiv.style.backgroundcolor = color;
 }
}

snake = {
 head : {},
 body : [],
 dire : 1
}

let headx = math.floor(math.random() * 14) + 3;
let heady = math.floor(math.random() * 14) + 3;
snake.head = new cell(headx, heady, headcolor);

//上右下左
let direction = [1, 2, 3, 4]

snake.dire = direction[math.floor(math.random() * 4)];

if(snake.dire == 1){
 snake.body.push(new cell(snake.head.x, snake.head.y+1, bodycolor));
 snake.body.push(new cell(snake.head.x, snake.head.y+2, bodycolor));
 snake.body.push(new cell(snake.head.x, snake.head.y+3, bodycolor));
}

if(snake.dire == 2){
 snake.body.push(new cell(snake.head.x-1, snake.head.y, bodycolor));
 snake.body.push(new cell(snake.head.x-2, snake.head.y, bodycolor));
 snake.body.push(new cell(snake.head.x-3, snake.head.y, bodycolor));
}

if(snake.dire == 3){
 snake.body.push(new cell(snake.head.x, snake.head.y-1, bodycolor));
 snake.body.push(new cell(snake.head.x, snake.head.y-2, bodycolor));
 snake.body.push(new cell(snake.head.x, snake.head.y-3, bodycolor));
}

if(snake.dire == 4){
 snake.body.push(new cell(snake.head.x+1, snake.head.y, bodycolor));
 snake.body.push(new cell(snake.head.x+2, snake.head.y, bodycolor));
 snake.body.push(new cell(snake.head.x+3, snake.head.y, bodycolor));
}

function game(){
 if(gamestaus == 'pause'){
 return;
 }
 if(gamestaus == 'gameover'){
 clearinterval(timer);
 alert('游戏结束');
 return;
 }
 initfood();
 let snakeheadx = snake.head.x;
 let snakeheady = snake.head.y;
 let color = '';
 if(snake.dire == 1){
 let tempdiv = document.getelementbyid(snakeheadx + 'div' + (snakeheady-1));
 if(tempdiv) color = tempdiv.style.backgroundcolor;
 snake.head = new cell(snakeheadx, snakeheady - 1, headcolor);
 }
 if(snake.dire == 2){
 let tempdiv = document.getelementbyid((snakeheadx + 1) + 'div' + snakeheady);
 if(tempdiv) color = tempdiv.style.backgroundcolor;
 snake.head = new cell(snakeheadx + 1, snakeheady, headcolor);
 }
 if(snake.dire == 3){
 let tempdiv = document.getelementbyid(snakeheadx + 'div' + (snakeheady+1));
 if(tempdiv) color = tempdiv.style.backgroundcolor;
 snake.head = new cell(snakeheadx, snakeheady + 1, headcolor);
 }
 if(snake.dire == 4){
 let tempdiv = document.getelementbyid((snakeheadx - 1) + 'div' + snakeheady);
 if(tempdiv) color = tempdiv.style.backgroundcolor;
 snake.head = new cell(snakeheadx - 1, snakeheady, headcolor);
 }
 snake.body.unshift(new cell(snakeheadx, snakeheady, bodycolor));
 if(color && color == foodcolor){
 hasfood = false;
 initfood();
 }else if(color && color == bodycolor){
 gamestaus = 'gameover'; 
 }else{
 let lastbody = snake.body.pop();
 new cell(lastbody.x, lastbody.y, '');
 }
}
var timer = setinterval(game, 10 / speed * 100)


/**
 * 初始化食物
 */
function initfood(){
 while(!hasfood){
 let x = math.floor(math.random() * row);
 let y = math.floor(math.random() * row);
 let snakebody = snake.body;
 let enable = true;
 if(snake.head.x == x && snake.head.y == y){
  enable = false;
 }
 for(sbody of snakebody){
  if(sbody.x == x && sbody.y == y){
  enable = false;
  break;
  }
 }
 if(enable){
  new cell(x, y, foodcolor);
  hasfood = true;
 }
 }
}

document.onkeydown = function(e){
 if(e.keycode == 38){
 //上
 if(snake.dire != 3 && snake.dire != 1){
  snake.dire = 1;
 }else if(snake.dire == 1){
  if(!hasaccelerate){
  clearinterval(timer);
  hasaccelerate = true;
  speed = speed * speedupmul;
  timer = setinterval(game, 10 / speed * 100)
  }
 }

 }

 if(e.keycode == 39){
 //右
 if(snake.dire != 4 && snake.dire != 2){
  snake.dire = 2;
 }else if(snake.dire == 2){
  if(!hasaccelerate){
  clearinterval(timer);
  hasaccelerate = true;
  speed = speed * speedupmul;
  timer = setinterval(game, 10 / speed * 100)
  }
 }
 }

 if(e.keycode == 40){
 //下
 if(snake.dire != 1 && snake.dire != 3){
  snake.dire = 3;
 }else if(snake.dire == 3){
  if(!hasaccelerate){
  clearinterval(timer);
  hasaccelerate = true;
  speed = speed * speedupmul;
  timer = setinterval(game, 10 / speed * 100)
  }
 }
 }

 if(e.keycode == 37){
 //左
 if(snake.dire != 2 && snake.dire != 4){
  snake.dire = 4;
 }else if(snake.dire == 4){
  if(!hasaccelerate){
  clearinterval(timer);
  hasaccelerate = true;
  speed = speed * speedupmul;
  timer = setinterval(game, 10 / speed * 100)
  }
 }
 }
 //空格键暂停
 if(e.keycode == 32){
 if(gamestaus == 'start'){
  gamestaus = 'pause';
 }else if(gamestaus == 'pause'){
  gamestaus = 'start';
 }
 }
}

document.onkeyup = function(e){
 if(e.keycode == 38){
 //上
 if(snake.dire == 1 && hasaccelerate){
  clearinterval(timer);
  hasaccelerate = false;
  speed = speed / speedupmul;
  timer = setinterval(game, 10 / speed * 100)
 }

 }

 if(e.keycode == 39){
 //右
  if(snake.dire == 2 && hasaccelerate){
  clearinterval(timer);
  hasaccelerate = false;
  speed = speed / speedupmul;
  timer = setinterval(game, 10 / speed * 100)
 }
 }

 if(e.keycode == 40){
 //下
  if(snake.dire == 3 && hasaccelerate){
  clearinterval(timer);
  hasaccelerate = false;
  speed = speed / speedupmul;
  timer = setinterval(game, 10 / speed * 100)
 }
 }

 if(e.keycode == 37){
 //左
 if(snake.dire == 4 && hasaccelerate){
  clearinterval(timer);
  hasaccelerate = false;
  speed = speed / speedupmul;
  timer = setinterval(game, 10 / speed * 100)
 }
 }
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。