我写博客的主要目的就是温习所学的知识，自己以前写的游戏当然不能放过！
这款网页版贪吃蛇是大一下册学习网页前端时老师教我们写的，由于那个时候初学网页前端，所以这款游戏是纯原生Java Script写的，没有使用JQuery。
重新看了一遍自己写的代码，大一的我真的太年轻了，一个注释都没有写，幸好这款游戏的逻辑不难，还能看得懂，补了一些注释，对一些细节加深了理解。（以后要逼着自己写注释才行呀！）
从大一寒假写C语言的俄罗斯方块开始，我就下定决心学一门编程语言，就用这门编程语言写一个游戏，这个目标也基本上实现了，陆陆续续写了C++推箱子、Python飞机大战，最近正在写Java打砖块，以后会慢慢跟大家分享的。
废话不多说，上代码！
DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width,initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>贪吃蛇title>
<script type="text/javascript">
var size = 20; //网格大小
var rows = 30; //网格行数
var cols = 40; //网格列数
var c;
var snake = []; //保存贪吃蛇的位置信息
var snake_len = 4; //贪吃蛇的长度
var foodx; //食物x坐标
var foody; //食物y坐标
var mark; //分数
var go = 3; //贪吃蛇爬行方向，左：1；上：2；右：3；下：4
var pause = true; //是否暂停
var interval; //游戏循环
function draw() {
c.clearRect(0, 0, size * cols, size * rows);
c.strokeStyle = "black";
for (var i = 1; i <= rows; i++) {
c.beginPath();
c.moveTo(0, i * size);
c.lineTo(size * cols, i * size);
c.closePath();
c.stroke();
} //画横线
for (var i = 1; i <= cols; i++) {
c.beginPath();
c.moveTo(i * size, 0);
c.lineTo(i * size, size * rows);
c.closePath();
c.stroke();
} //画竖线
c.strokeStyle = "white";
c.fillStyle = "green";
for (var i = 0; i < snake_len; i++) {
c.beginPath();
c.fillRect(snake[i].x, snake[i].y, size, size);
c.moveTo(snake[i].x, snake[i].y);
c.lineTo(snake[i].x + size, snake[i].y);
c.lineTo(snake[i].x + size, snake[i].y + size);
c.lineTo(snake[i].x, snake[i].y + size);
c.closePath();
c.stroke();
} //画贪吃蛇
c.fillStyle = "yellow";
c.beginPath();
c.fillRect(foodx, foody, size, size);
c.moveTo(foodx, foody);
c.lineTo(foodx + size, foody);
c.lineTo(foodx + size, foody + size);
c.lineTo(foodx, foody + size);
c.closePath();
c.stroke(); //画食物
}
function addfood() {
foodx = Math.floor(Math.random() * (cols - 1)) * size;
foody = Math.floor(Math.random() * (rows - 1)) * size;
while (foodx == 0) {
foodx = Math.floor(Math.random() * (cols - 1)) * size;
}
while (foody == 0) {
foody = Math.floor(Math.random() * (rows - 1)) * size;
}
} //设置食物位置，保证不为第一行(列)、最后一行(列)
function start() {
for (var i = 0; i < snake_len; i++) {
snake[i] = {
x: i * size,
y: 0
}
} //设置贪吃蛇出现的位置
addfood();
draw();
mark.innerHTML = 0;
}
function addsnake() {
snake_len++;
snake.unshift({
x: size * cols,
y: size * rows
}); //添加新方块至网格外，会在下个游戏循环添加至贪吃蛇
}
function IsEat() {
if (snake[snake_len - 1].x == foodx && snake[snake_len - 1].y == foody) {
mark.innerHTML = (parseInt(mark.innerHTML) + 1).toString();
addfood();
addsnake();
}
}
function IsDie() {
if (snake[snake_len - 1].x == -1 * size || snake[snake_len - 1].y == -1 * size ||
snake[snake_len - 1].x == cols * size || snake[snake_len - 1].y == rows * size) {
clearInterval(interval);
alert("Game Over!没有玩过瘾，那就刷新页面再来一次。");
} //贪吃蛇爬行到网格外
for (var i = 0; i < snake_len - 1; i++) {
if (snake[i].x == snake[snake_len - 1].x && snake[i].y == snake[snake_len - 1].y) {
clearInterval(interval);
alert("Game Over!没有玩过瘾，那就刷新页面再来一次。");
}
} //贪吃蛇缠绕
}
function move() {
switch (go) {
case 1:
snake.push({
x: snake[snake_len - 1].x - size,
y: snake[snake_len - 1].y
});
break;
case 2:
snake.push({
x: snake[snake_len - 1].x,
y: snake[snake_len - 1].y - size
});
break;
case 3:
snake.push({
x: snake[snake_len - 1].x + size,
y: snake[snake_len - 1].y
});
break;
case 4:
snake.push({
x: snake[snake_len - 1].x,
y: snake[snake_len - 1].y + size
});
}
snake.shift();
IsEat();
IsDie();
draw();
} //游戏循环
function keydown(keyCode) {
switch (keyCode) {
case 37:
if (go != 1 && go != 3)
go = 1;
break;
case 38:
if (go != 2 && go != 4)
go = 2;
break;
case 39:
if (go != 3 && go != 1)
go = 3;
break;
case 40:
if (go != 4 && go != 2)
go = 4;
break;
case 32:
if (pause) {
interval = setInterval(move, 130); //开始游戏循环
pause = false;
document.getElementById('pause').innerHTML = "Pause";
} else {
clearInterval(interval);
pause = true;
document.getElementById('pause').innerHTML = "Satrt";
}
break;
}
} //键盘操作
window.onload = function () {
c = document.getElementById('canvas').getContext('2d');
mark = document.getElementById('score');
start();
document.onkeydown = function (event) {
var event = event || window.event;
keydown(event.keyCode);
}
}
script>
<style>
#page {
margin-left: auto;
margin-right: auto;
margin-top: 20px;
width: 1000px;
height: 600px;
}
#yard {
width: 800px;
border: 1px solid gray;
box-shadow: 0 0 10px #000;
float: right;
}
#mark {
font-weight: 800;
}
#score {
color: #f00;
}
button {
width: 50px;
}
p {
margin-left: 40px;
}
style>
head>
<body>
<div id="page">
<div id="yard">
<canvas id="canvas" width="800" height="600">canvas>
div>
<div id="help">
<div id="mark">Mark:<span id="score">span>div>
<div id="helper">
<table>
<tr>
<td>td>
<td>
<button onclick="keydown(38)">Upbutton>
td>
<td>td>
tr>
<tr>
<td>
<button onclick="keydown(37)">Leftbutton>
td>
<td>
<button onclick="keydown(32)" id="pause">Satrtbutton>
td>
<td>
<button onclick="keydown(39)">Rightbutton>
td>
tr>
<tr>
<td>td>
<td>
<button onclick="keydown(40)">Downbutton>
td>
<td>td>
tr>
table>
<p>空格键暂停p>
div>
div>
div>
body>
html>
效果图：
试玩：http://static.pzijigame.com/Game/snake.html（PC端才能玩哦！！！）
有感兴趣的朋友可以直接私聊我（[email protected]），我们可以一起讨论，一起进步！！！