本文实例为大家分享了js贪吃蛇游戏的相关代码，供大家参考，具体内容如下
<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <title>贪吃蛇小游戏</title> <style>*{margin:0; padding:0;}header { display: block; margin: 0 auto; width: 500px; text-align: center;}header h1 { font-family: Arial; font-weight: bold;}header #newGameButton { display: block; margin: 20px auto; width: 100px; padding: 10px 10px; background-color: #8f7a66; font-family: Arial; color: white; border-radius: 10px; text-decoration: none;}header #newGameButton:hover { background-color: #9f8b77;}header p { font-family: Arial; font-size: 25px; margin: 20px auto;}canvas{ display:block; border:medium double black; margin:4px auto;} </style></head><body> <header> <h1>贪吃蛇小游戏</h1> <a href="javascript:newgame();" id="newGameButton">New Game</a> <p>score:<span id="score">0</span></p> </header> <canvas id="canvas"> Your browser doesn't support the <code>canvas</code> element. </canvas> <script> var CANVAS = document.getElementById("canvas");var CTX = CANVAS.getContext("2d");var SNAKE = new Array(); //用队列模拟蛇身var DIR = "right"; //用来控制蛇头的方向var SIZE = 20; //蛇身的宽度var FOODX = 0; //食物的x坐标var FOODY = 0; //食物的y坐标var HEADX = 0; //蛇头的x坐标var HEADY = 0; //蛇头的y坐标var MAXWIDTH = 200; //画布的高度var MAXHEIGHT = 200; //画布的宽度var TIME = 400; //蛇的速度var SCORE = 0; //计算玩家分数var interval = null;CANVAS.width = MAXWIDTH;CANVAS.height = MAXHEIGHT;window.onload = function(){ newgame();};document.getElementById("newGameButton").click(function(){ newgame();});function newgame(){ SNAKE = []; //用队列模拟蛇身 DIR = "right"; //用来控制蛇头的方向 HEADX = 0; //蛇头的x坐标 HEADY = 0; //蛇头的y坐标 SCORE = 0; window.clearInterval(interval); interval = null; //初始化画布 CTX.clearRect(0, 0, MAXWIDTH, MAXHEIGHT); //画一条蛇 drawSnake(); //放置食物 setFood(); //移动蛇 interval = window.setInterval(move, TIME);}function move(){ switch(DIR){ case "up":HEADY = HEADY-SIZE;break; case "right":HEADX = HEADX+SIZE;break; case "down":HEADY = HEADY+SIZE;break; case "left":HEADX = HEADX-SIZE;break; } if(HEADX>MAXWIDTH-SIZE || HEADY>MAXHEIGHT-SIZE || HEADX<0 || HEADY<0){ alert("你的分数为："+SCORE+"分，继续努力吧!失败原因：碰壁了....."); window.location.reload(); } for(var i=1;i<SNAKE.length;i++){ if(SNAKE[i][0] == SNAKE[0][0] && SNAKE[i][1] == SNAKE[0][1]){ alert("你的分数为："+SCORE+"分，继续努力吧！失败原因：撞到自己了....."); window.location.reload(); } } if(SNAKE.length == MAXWIDTH *MAXHEIGHT){ alert("好厉害!么么哒~"); window.location.reload(); } moveIn(HEADX, HEADY);//移动一格}document.onkeydown = function(e) { //改变蛇方向 var code = e.keyCode - 37; switch(code){ case 1 : DIR = "up";break;//上 case 2 : DIR = "right";break;//右 case 3 : DIR = "down";break;//下 case 0 : DIR = "left";break;//左 }}//=============================画一条蛇=======================================================function drawSnake(){ CTX.fillStyle = "black"; //画蛇头 CTX.fillRect (HEADX, HEADY, SIZE, SIZE); SNAKE.push([HEADX, HEADY]); //画蛇身 switch(DIR){ case "up": drawBody(HEADX, HEADY + SIZE, HEADX, HEADY + 2 * SIZE); break; case "right": drawBody(HEADX - SIZE, HEADY, HEADX - 2 * SIZE, HEADY); break; case "down": drawBody(HEADX, HEADY - SIZE, HEADX, HEADY - 2 * SIZE); break; case "left": drawBody(HEADX + SIZE, HEADY, HEADX + 2 * SIZE, HEADY); break; }}function drawBody(x1, y1, x2, y2){ CTX.fillRect (x1, y1, SIZE, SIZE); CTX.fillRect (x2, y2, SIZE, SIZE); SNAKE.push([x1, y1]); SNAKE.push([x2, y2]);}//===========================放置食物==============================function setFood(){ do{ FOODX = SIZE * Math.floor(Math.random() * MAXWIDTH / SIZE); FOODY = SIZE * Math.floor(Math.random() * MAXHEIGHT / SIZE); }while(foodInSnake()); CTX.fillStyle = "red"; CTX.fillRect (FOODX, FOODY, SIZE, SIZE);}function foodInSnake(){ for (var i = 0; i < SNAKE.length; i++) { if(FOODX == SNAKE[i][0] && FOODY == SNAKE[i][1]){ return true; } } return false;}//========================================移动一格===========================function moveIn(x, y){ CTX.fillStyle = "black"; CTX.fillRect(x, y, SIZE, SIZE);//重画蛇头 //把新蛇头添加到 SNAKE 数组 var newSnake = [[x, y]]; SNAKE = newSnake.concat(SNAKE); if(false == eatFood()){//如果没吃到食物，减少一格蛇尾 var snakeTail = SNAKE.pop();//获得蛇尾位置 CTX.clearRect(snakeTail[0], snakeTail[1], SIZE, SIZE);//去掉蛇尾 }}function eatFood(){ if(HEADX == FOODX && HEADY == FOODY){ CTX.fillStyle = "block"; CTX.fillRect (FOODX, FOODY, SIZE, SIZE); setFood(); SCORE++; //$("#score").text(SCORE); document.getElementById("score").innerHTML = SCORE; return true; } return false;} </script></html>效果图：
思路：
function newgame(){ 重置蛇和分数的数据； 清除interval； 初始化画布； 画一条蛇； 放置食物； 使用定时器（setInterval）使蛇移动（move函数）；}function move(){ 根据方向改变蛇头下一格将要到达的位置； 判断游戏是否结束，以及显示结束的原因（包含输赢）； 蛇移动一格（moveIn函数）；}对键盘的方向键作监控，当改变方向时，修改全局变量DIR的值（用于存储方向）；function moveIn(){ 在蛇头的前一格增加一格作为新的蛇头，并将蛇头的坐标作为第一个元素加入到代表蛇的数组中； if(没吃到食物){ 删除一格蛇尾，在画布中做相应改变； }}需要注意的是，如果需要在JS中设定canvas中的宽度和高度，和设置其他CSS属性略有不同。
CANVAS.width = MAXWIDTH;CANVAS.height = MAXHEIGHT;
小编还为大家准备了精彩的专题：javascript经典小游戏汇总
以上就是本文的全部内容，希望对大家学习javascript程序设计有所帮助。