Code to implement the snake game using js-JS Tutorial-php.cn

Code to implement the snake game using js

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Release： 2018-07-14 16:12:38

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This article mainly introduces the code about using js to implement the snake game. It has a certain reference value. Now I share it with you. Friends in need can refer to it

One-dimensional array^700char

##The snake body at (0,0) position It is represented by 0, (0,1) is represented by 1, (1,0) is represented by 10, and so on

Because it is 13 line js,

Line 4 is a statement

Line 5 is more difficult To understand, you can split the ?: operator into 4 lines of if statements; you can refer to the following two-dimensional array version

Line 90|x Both ~~x and x>>0 can remove the mantissa of x(number)

It should be easy to read

<!DOCTYPE html>
<canvas id="1" width="400" height="400"></canvas> 
<script> 
let dir=1,food=3,snk=[1,0],ctx=document.getElementById("1").getContext("2d")
document.onkeydown=e=>{dir =  snk[0]-snk[1]==-(tmp = [-1,-10,1,10][e.keyCode-37]||dir)?dir:tmp }
setInterval(()=>{
    snk.unshift(Head = snk[0] + dir)
    if(Head!=food) snk.pop()
    else while(snk.includes(food=0|Math.random()*10*10)) ;
    if(snk.indexOf(Head,1)!=-1||(dir==1&&Head%10==0)||(dir==-1&&Head%10==9)||Head<0||Head>=100)
        return document.write(0&snk.shift()) //死亡记录蛇长
    for(let i=0; i<100; i++){
        ctx.fillStyle = &#39;#0&#39;+(food==i)*9910+snk.includes(i)*1990
        ctx.fillRect(i%10*40,(i-i%10)*4, 40,40)
    }
},100) 
</script>

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Color Effect

<!DOCTYPE html>
<canvas id="1" width="400" height="400"></canvas>
<script>
let dir=1,food=3,snk=[1,0],n_=0, ctx=document.getElementById("1").getContext("2d")
document.onkeydown=e=>{ dir =snk[0]-snk[1]==-(tmp = [-1,-10,1,10][e.keyCode-37]||dir)?dir:tmp }
setInterval(()=>{
    snk.unshift(Head = snk[0] + dir)
    if(Head!=food) snk.pop()
    else while(snk.includes(food=0|Math.random()*10*10)) ;
    if(snk.indexOf(Head,1)!=-1||(dir==1&&Head%10==0)||(dir==-1&&Head%10==9)||Head<0||Head>=100)
        return alert("died"+ ++n_+"times") //死亡记录死亡次数
    for(let i=0 ; i<100; i++){
        ctx.fillStyle = &#39;#0&#39;+~~((food===i)*13000*Math.random())+~~(snk.includes(i)*3000*Math.random())
        ctx.fillRect(i%10*40,(i-i%10)*4, 40,40)
    }
},120)
</script>

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Instructions

If you want to write it yourself:You should pay attention to two points

The snake's tail should disappear before the snake's head,The snake's head should be generated before the food,
Snake cannot walkCurrentlyThe opposite direction
can be used A snake of length 4 is tested

##Coding style

Omit unnecessary tags
https://google.github.io/styleguide/htmlcssguide.html#Optional_Tags
if() return only uses one line
https://google.github.io/styleguide/cppguide.html
Except for keyboard response where using the
3 operator can save 3 lines, there is no need to use in other places

Two-dimensional array

The above are all implemented using one-dimensional arrays, and the following are written using two-dimensional arrays; to simplify It can also be simplified to within 17 lines

900char (just shorter than the 20-line one), but there is no need for

with comments 1100char

<!DOCTYPE html>
<canvas id="1" width="400" height="400" style="border: 1px solid "></canvas>
<script>
    ctx = document.getElementById("1").getContext("2d") //CanvasRenderingContext2D inferface
    let Len = 10, dir = 2, dirNow ; //dirNow 后面解释
    food = [3, 0]; Snake = [[0, 0], [1, 0]] //食物的坐标,蛇身的坐标用Snake数组记录
    Map = {&#39;0,0&#39;:&#39;#52a&#39;, &#39;1,0&#39;:&#39;#52a&#39;} //用来记录绘图颜色的 地图
    dirMat = [[-1, 0], [0, -1], [1, 0], [0, 1]] //方向矩阵
    pairEq = ((p1, p2) => p1[0] == p2[0] && p1[1] == p2[1]) //检测 两数对 是否相等的函数
    document.onkeydown = e =>{
        if (37 <= e.keyCode == e.keyCode < 41 && dirNow != ( (e.keyCode - 35) % 4) ) //确定是 方向键 并且 保证方向与当前运动方向相反
            dir = e.keyCode -37
    }
    !function () {
        Head = Snake[Snake.length-1].map((x, i) => x + dirMat[dirNow=dir][i]); //得到头部接下来的移动位置
        if (!pairEq(Head, food))
            Map[Snake.shift()]=&#39;#fff&#39; //必须先删尾巴,才能加入头部,吃没吃到食物是唯一判断标准
        if (Snake.some(x=>pairEq(x,Head)) || !Head.every(x => 0<=x == x < Len)) //判断蛇头是否撞到蛇身或墙壁
            return document.write("Game Over") //这样调用document.write会把页面全部清空
        Snake.push(Head); //可以加入头部
        while (Snake.some(x => pairEq(x, food))) //加入新头后, 生成食物更方便
            food = [~~(Math.random() * Len), ~~(Math.random() * Len)]; //因为js没有整形的概念, ~~ 现在相当于向原点舍去
        Map[Head] = &#39;#52a&#39; ; Map[food] = &#39;#ad5&#39;
        for( k in Map){
            ctx.fillStyle= Map[k]
            ctx.fillRect(parseInt(k[0])*40,parseInt(k[2])*40,40,40) //e.g. k="1,3",也因此地图大小限制为10
        }
        setTimeout(arguments.callee, 100); //100ms后调用此函数一次
    }()
</script>

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Colorful

(Mainly more beautiful )1100char

<!DOCTYPE html>
<canvas id="1" width="400" height="400" style="border: 1px solid " ></canvas>
<script>
    ctx = document.getElementById("1").getContext("2d")
    let Len = 10, dir = 2, dirNow ;
food = [3, 0]; Snake = [[0, 0], [1, 0]]
    Map = {&#39;0,0&#39;:&#39;fff&#39;, &#39;1,0&#39;:&#39;fff&#39;}
    dirMat = [[-1, 0], [0, -1], [1, 0], [0, 1]]
    pairEq = ((p1, p2) => p1[0] == p2[0] && p1[1] == p2[1])
    document.onkeydown = e =>{
        if (37 <= e.keyCode == e.keyCode < 41 && dirNow != ( (e.keyCode - 35) % 4) )
dir = e.keyCode -37
    }
    !function () {
        Head = Snake[Snake.length-1].map((x, i) => x + dirMat[dirNow=dir][i]);
        if (!pairEq(Head, food)) Map[Snake.shift()]=&#39;0&#39;
        if (Snake.some(x=>pairEq(x,Head)) || !Head.every(x => 0<=x == x < Len))
            return document.write("Game Over")
        Snake.push(Head);
        while (Snake.some(x => pairEq(x, food)))
food = [~~(Math.random() * Len), ~~(Math.random() * Len)];
        Map[Head] = Map[food] = &#39;fff&#39;
        for( k in Map){
            ctx.fillStyle=&#39;#&#39;+(0xfff-~~(parseInt(Map[k],16)*Math.random())).toString(16)
            ctx.fillRect(parseInt(k[0])*40,parseInt(k[2])*40,46,43)
        }
        setTimeout(arguments.callee, 100);
    }()
</script>

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#13 Line regular (700 bytes)	shortest snake game.html
Compressed 500 bytes (of course the two documents can still be compressed with eval)	index.500bytes.html
It was very popular before 20 lines of code address (with BUG) (900bytes)	##hj7jay/article/details/51011269

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