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)
}
}
}

来源：https://blog.csdn.net/weixin_42525191/article/details/114670004