本文实例为大家分享了javascript实现贪吃蛇游戏的具体代码，供大家参考，具体内容如下
一共三个对象map，snake，food，代表的含义如名字。snake和food其实就是数组，表示位置，map来画图、判断得分、失败等等，直接上代码，可直接运行。
<!doctype html>
<html>
<body>
<canvas id="map" width="400" height="400" style="background:Black"></canvas>
<h1>Score:</h1>
<h2 id="score">0</h2>
<script>
//地图
function Map() {
this.field = document.getElementById("map").getContext("2d"); //画布
this.draw = function (something) { //画蛇或者食物
this.field.fillStyle = something.color;
var position;
for (position in something.positions) {
this.field.fillRect(something.positions[position][0], something.positions[position][1], 20, 20);
}
}
this.clear = function () { //清除画布
this.field.clearRect(0, 0, 400, 400);
}
this.judge = function (snake, food) { //判断状态（得分、失败、普通）
var snakeHeadX = snake.positions[0][0];
var snakeHeadY = snake.positions[0][1];
var foodX = food.positions[0][0];
var foodY = food.positions[0][1];
if ((snakeHeadX == foodX) && (snakeHeadY == foodY)) { //吃食物
snake.positions.unshift([foodX, foodY]);
food.positions[0] = [Math.floor(Math.random() * 20) * 20, Math.floor(Math.random() * 20) * 20];
this.clear();
this.draw(food);
this.draw(snake);
var score = document.getElementById('score');
score.innerHTML = (Number(score.innerHTML)+1).toString();
}
else if ((snakeHeadX+20 > 400) || (snakeHeadX < 0) || (snakeHeadY+20 > 400) || (snakeHeadY < 0)) {
alert('GIME OVER!'); //撞墙
}
else {
this.clear();
this.draw(food);
this.draw(snake);
}
}
}
//蛇
function Snake() {
this.positions = [[40 + 20, 40], [40, 40], [40 - 20, 40]]; //蛇的躯干
this.color = "Yellow";
this.direction = [1,0]; //蛇头方向
this.move = function () { //移动
this.positions.unshift([this.positions[0][0] + this.direction[0] * 20, this.positions[0][1] + this.direction[1] * 20]);
this.positions.pop();
}
this.obeyOrders = function (snake = this) { //等待键盘上下左右
document.onkeydown = function (event) {
var e = event || window.event || arguments.callee.caller.arguments[0];
var order = e.keyCode;
console.log(snake.direction);
switch (order) {
case 37:
snake.direction[0] = -1;
snake.direction[1] = 0;
break;
case 38:
snake.direction[1] = -1;
snake.direction[0] = 0;
break;
case 39:
snake.direction[0] = 1;
snake.direction[1] = 0;
break;
case 40:
snake.direction[1] = 1;
snake.direction[0] = 0;
break;
default:
;
}
};
}
}
//食物
function Food() {
this.positions = [[Math.floor(Math.random() * 20) * 20, Math.floor(Math.random() * 20) * 20]]; //随机位置
this.color = 'Red';
}
//开始执行
(function () {
var map = new Map();
var snake = new Snake();
var food = new Food();
map.draw(snake);
map.draw(food);
snake.obeyOrders();
var t=0;
var interval = setInterval(function () { //每0.5s走一步
map.judge(snake, food);
snake.move();
}, 500);
})()
</script>
</body>
</html>
效果如图
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。