本文實例為大家分享了js貪吃蛇遊戲的相關代碼，供大家參考，具體內容如下
<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <title>貪吃蛇小遊戲</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>貪吃蛇小遊戲</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(); //用隊列模擬蛇身var DIR = "right"; //用來控制蛇頭的方向var SIZE = 20; //蛇身的寬度var FOODX = 0; //食物的x坐標var FOODY = 0; //食物的y坐標var HEADX = 0; //蛇頭的x坐標var HEADY = 0; //蛇頭的y坐標var MAXWIDTH = 200; //畫布的高度var MAXHEIGHT = 200; //畫布的寬度var TIME = 400; //蛇的速度var SCORE = 0; //計算玩家分數var interval = null;CANVAS.width = MAXWIDTH;CANVAS.height = MAXHEIGHT;window.onload = function(){ newgame();};document.getElementById("newGameButton").click(function(){ newgame();});function newgame(){ SNAKE = []; //用隊列模擬蛇身DIR = "right"; //用來控制蛇頭的方向HEADX = 0; //蛇頭的x坐標HEADY = 0; //蛇頭的y坐標SCORE = 0; window.clearInterval(interval); interval = null; //初始化畫布CTX.clearRect(0, 0, MAXWIDTH, MAXHEIGHT); //畫一條蛇drawSnake(); //放置食物setFood(); //移動蛇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("你的分數為："+SCORE+"分，繼續努力吧!失敗原因：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("你的分數為："+SCORE+"分，繼續努力吧！失敗原因：撞到自己了....."); window.location.reload(); } } if(SNAKE.length == MAXWIDTH *MAXHEIGHT){ alert("好厲害!麼麼噠~"); window.location.reload(); } moveIn(HEADX, HEADY);//移動一格}document.onkeydown = function(e) { //改變蛇方向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}}//=============================畫一條蛇=======================================================function drawSnake(){ CTX.fillStyle = "black"; //畫蛇頭CTX.fillRect (HEADX, HEADY, SIZE, SIZE); SNAKE.push([HEADX, HEADY]); //畫蛇身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;}//========================================移動一格===========================function moveIn(x, y){ CTX.fillStyle = "black"; CTX.fillRect(x, y, SIZE, SIZE);//重畫蛇頭//把新蛇頭添加到SNAKE 數組var newSnake = [[x, y]]; SNAKE = newSnake.concat(SNAKE); if(false == eatFood()){//如果沒吃到食物，減少一格蛇尾var snakeTail = SNAKE.pop();//獲得蛇尾位置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>效果圖：
思路：
function newgame(){ 重置蛇和分數的數據； 清除interval； 初始化畫布； 畫一條蛇； 放置食物； 使用定時器（setInterval）使蛇移動（move函數）；}function move(){ 根據方向改變蛇頭下一格將要到達的位置； 判斷遊戲是否結束，以及顯示結束的原因（包含輸贏）； 蛇移動一格（moveIn函數）；}對鍵盤的方向鍵作監控，當改變方向時，修改全局變量DIR的值（用於存儲方向）；function moveIn(){ 在蛇頭的前一格增加一格作為新的蛇頭，並將蛇頭的坐標作為第一個元素加入到代表蛇的數組中； if(沒吃到食物){ 刪除一格蛇尾，在畫布中做相應改變； }}需要注意的是，如果需要在JS中設定canvas中的寬度和高度，和設置其他CSS屬性略有不同。
CANVAS.width = MAXWIDTH;CANVAS.height = MAXHEIGHT;
小編還為大家準備了精彩的專題：javascript經典小遊戲匯總
以上就是本文的全部內容，希望對大家學習javascript程序設計有所幫助。