原生js编写贪吃蛇小游戏

本文实例为大家分享了js编写贪吃蛇小游戏的具体代码，供大家参考，具体内容如下

刚学完js模仿着教程，把自己写的js原生小程序。

HTML部分

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" href="./css/index.css" rel="external nofollow"  >
</head>
<body>
    <div class="content">
     <!-- 游戏开启按钮 -->
        <div class="btn startBtn"><button></button></div>
        <!-- 蛇身 -->
        <div id="snakeWrap"></div>
    </div>
    <!-- 引入外部js文件 -->
    <script src="./js/index.js"></script>
</body>
</html>

css部分

/* 整体样式 */
.content{
    width: 640px;
    height: 640px;
    margin: 100px auto;
    position: relative;
}
 .btn{
    width: 100%;
    height: 100%;
    position: absolute;
    left: 0;
    top: 0;
    background-color: rgba(0, 0, 0, 0.3);
    z-index: 2;
}

.btn button{
    background: none;
    border: none;
    background-size: 100% 100%;

    cursor: pointer;
    outline: none;

    position: absolute;
    left: 50%;
    top: 50%;
}

.startBtn button{
    width: 200px;
    height: 80px;
    background: url(../images/Snipaste_2021-05-08_08-52-45.png) no-repeat;
    background-size: contain;
    margin-left: -100px;
    margin-top: 222px;
}

#snakeWrap{
    width: 600px;
    height: 600px;
    background: #73aad4;
    border: 20px solid #13649c;
    position: relative;
}

.snakeHead{
    background-color: yellowgreen;
    border-radius: 50%;
}

.snakeBody{
    background-color: black;
    border-radius: 50%;
}

.food{
    background-color: red;
    border-radius: 50%;
}

js部分

var sw = 20,        //一个方块的宽
    sh = 20,        //一个方块的宽
    tr = 30,        //行数
    td = 30;        //列数

var snake = null,  //生成蛇的实例
    food = null;    //生成食物的实例
    game = null;   //创建游戏实例
    
//把整体看成是一个一个小方块 移动的的时候创建和删除方块(后续所有方块的生成都会调用)
// 方块构造函数
function Square(x,y,classname){    //对应css中三种蛇的样式（蛇头 蛇身 蛇尾）
    this.x = x * sw;
    this.y = y * sh;
    this.class = classname;
    this.viewContent = document.createElement('div');
    this.viewContent.className = this.class;             //将创建出来的div添加对应css样式
    this.parent = document.getElementById('snakeWrap');    
}

//在方块构造函数的 原型链 上创建create方法 确定新div的具体信息
//this指向Square
Square.prototype.create = function(){
    this.viewContent.style.position = 'absolute';
    this.viewContent.style.width = sw + 'px';
    this.viewContent.style.height = sh + 'px';
    this.viewContent.style.left = this.x + 'px';
    this.viewContent.style.top = this.y + 'px';

    this.parent.appendChild(this.viewContent);     //把新创建的div添加到页面
}

//在方块构造函数的 原型链 上创建remove方法  用于移动时删除方块
Square.prototype.remove = function(){
    this.parent.removeChild(this.viewContent);
}

// 蛇
function Snake(){
    this.head = null;       //存储蛇头信息
    this.tail = null;       //存储蛇尾信息
    this.pos = [];          //存储蛇身上的每一个方块的位置

    this.directionNum = {   //存储蛇走的方向
        left : {
            x : -1,
            y : 0
        },
        right : {
            x : 1,
            y : 0
        },
        up : {
            x : 0,
            y : -1
        },
        down : {
            x : 0,
            y : 1
        }
    }
}

//this 指向 Snake
Snake.prototype.init = function(){      //初始化
    // 创建蛇头
    var snakeHead = new Square(2,0,'snakeHead');
    snakeHead.create();
    this.head = snakeHead;
    this.pos.push([2,0]);       //储存蛇头信息

    // 创建蛇身1
    var snakeBody1 = new Square(1,0,'snakeBody');
    snakeBody1.create();
    this.pos.push([1,0]);       //储存蛇身信息

    // 创建蛇尾
    var snakeBody2 = new Square(0,0,'snakeBody');
    snakeBody2.create();
    this.tail = snakeBody2;
    this.pos.push([0,0]);       /储存蛇尾信心

    //形成链表关系
    //蛇头 蛇身 蛇尾的前后关系
    snakeHead.last = null;
    snakeHead.next = snakeBody1;

    snakeBody1.last = snakeHead;
    snakeBody1.next = snakeBody2;

    snakeBody2.last = snakeBody1;
    snakeBody2.next = null;

    //给蛇 添加一个默认方向 向右
    this.direction = this.directionNum.right;
}

// 获取蛇头的下一个位置对应的元素（this指向Snake）
// 获取下一个点的坐标并储存到nextPos数组
Snake.prototype.getNextPos = function(){
    var nextPos = [
        this.head.x/sw + this.direction.x,         //this.direction.x、y 下面会将方向与键盘事件绑定 来确定下一个点生成的位置
        this.head.y/sh + this.direction.y
    ]
    
    // 下个点是自己，撞到了自己  游戏结束
    var selfCollied = false;
    this.pos.forEach(function(value){            //forEach遍历数组 两数组比较看是否有重复坐标
        if (value[0] == nextPos[0] && value[1] == nextPos[1]){
            selfCollied = true;
        }
    })
 
 //撞到了自己  游戏结束
    if(selfCollied){
        this.、
        .die.call(this);
        return;
    }

    // 下个点是围墙  游戏结束
    
    if(nextPos[0] > 29 || nextPos[0] < 0 || nextPos[1] > 29 || nextPos[1] < 0){
        this.strategies.die.call(this);
        return;
    }

    // 下个点是食物  吃

    if(food && food.pos[0] == nextPos[0] && food.pos[1] == nextPos[1]){
        this.strategies.eat.call(this);
        return;
    }

    // 下个点什么都不是  走

    this.strategies.move.call(this);
}


// 碰撞后要做的事

Snake.prototype.strategies = {
    move : function(format){ //参数用于判断是否删除蛇尾
        // 创建一个newbody,删掉蛇头
        var newBody = new Square(this.head.x/sw,this.head.y/sh,'snakeBody')
        newBody.next = this.head.next;
        newBody.next.last = newBody;
        newBody.last = null;
        this.head.remove();
        newBody.create();

        // 创建一个新蛇头
        var newx = this.head.x/sw + this.direction.x;
        var newy = this.head.y/sh + this.direction.y;
        var newHead = new Square(newx,newy,'snakeHead')
        newHead.next = newBody;
        newBody.last = newHead;
        newHead.last = null;
        newHead.create();

        // 更新蛇身的坐标
        this.pos.splice(0,0,[newx,newy]);
        this.head = newHead;

        //如果为false  则吃
        if(!format){
            this.tail.remove();
            this.tail = this.tail.last;

            this.pos.pop();
        }
    },
    eat : function(){
        this.strategies.move.call(this,true);
        game.score ++;
        createFood();
    },
    die : function(){
        game.over();
    }
}


snake = new Snake();


// 创建食物
function createFood(){
    // 食物小方块坐标
    var x = null;
    var y = null;

    var include = true;
    while(include){
        x = Math.round(Math.random()*(td - 1));
        y = Math.round(Math.random()*(tr - 1));

        snake.pos.forEach(function(value){
            if(x != value[0] && y != value[1]){
                include = false;
            }
        });
    }
    // 生成食物
    food = new Square(x,y,'food');
    food.pos = [x,y];

    var foodDom = document.querySelector('.food');
    if(foodDom){
        foodDom.style.left = x * sw + 'px';
        foodDom.style.top = y * sh + 'px';
    }else{
        food.create();
    }
}



// 创建游戏逻辑
function Game(){
    this.timer = null;
    this.score = 0;
}

Game.prototype.init = function(){
    snake.init();
    createFood();
 //这里曾经的e.keycode e.which 都已禁用  使用e.key
    window.addEventListener('keydown',function(e){
        if(e.key == 'ArrowLeft' && snake.direction != snake.directionNum.right){
            snake.direction = snake.directionNum.left;
        }else if(e.key == 'ArrowUp' && snake.direction != snake.directionNum.down){
            snake.direction = snake.directionNum.up;
        }else if(e.key == 'ArrowRight' && snake.direction != snake.directionNum.left){
            snake.direction = snake.directionNum.right;
        }else if(e.key == 'ArrowDown' && snake.direction != snake.directionNum.up){
            snake.direction = snake.directionNum.down;
        }
    });
    this.start();
}

Game.prototype.start = function(){
    this.timer = setInterval(function(){
        snake.getNextPos();
    },0.0000000000000001)
}

Game.prototype.over = function(){
    clearInterval(this.timer);
    alert('你的得分为' + this.score);


    // 游戏回到最初始状态
    var snakeWrap = document.getElementById('snakeWrap');
    snakeWrap.innerHTML = '';

    snake = new Snake();
    game = new Game();

    var startBtnWrap = document.querySelector('.startBtn');
    startBtnWrap.style.display = 'block';
}

// 开启游戏

game = new Game();
var startBtn = document.querySelector('.startBtn button');
startBtn.onclick = function(){
    startBtn.parentNode.style.display = 'none';
    game.init();
}

简单的一个小游戏，如有问题请大佬指正。

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NICE源码。

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