Hello World 对于每一个开发者来说都不陌生,因为在我们学习任何一个语言或框架的时候,都会有一个Hello World的案例来帮助我们快速入门。

如果我们使用JavaScript来输出Hello World的话,可以这样写:

alert("Hello World");

放入HTML:

<html>
<script type="text/javascript">
alert("Hello World");
</script>
</html>

在浏览器中打开就可以如下情况输出Hello World了:

挑战:仅用六种字符来编写JavaScripte

上面我们在JavaScript中实现Hello World的时候,除去HTML相关的标签和属性,上面的实现语句alert("Hello World");一共使用了13个字符,那么有没有办法用更少的字符来实现一样的功能呢?今天我们就来挑战一下:有没有办法仅使用6个字符来编写JavaScripte程序,以实现Hello World的输出?

...

...

...

先思考一下,有思路没?没思路的话,下面有提示...

...

...

...

...

...

...

...

提示:使用这六个字符:(,),+,[,],!

...

...

...

...

...

...

...

再思考一下,有思路没?没思路的话,下面有答案和解析...

...

...

...

...

...

...

...

答案:

<html>
<script type="text/javascript">
[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]][([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([][[]]+[])[+!+[]]+(![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+[]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+(!![]+[])[+!+[]]]((!![]+[])[+!+[]]+(!![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+([][[]]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+!+[]]+(+[![]]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+!+[]]]+(!![]+[])[!+[]+!+[]+!+[]]+(+(!+[]+!+[]+!+[]+[+!+[]]))[(!![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([]+[])[([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([][[]]+[])[+!+[]]+(![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+[]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+(!![]+[])[+!+[]]][([][[]]+[])[+!+[]]+(![]+[])[+!+[]]+((+[])[([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([][[]]+[])[+!+[]]+(![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+[]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+(!![]+[])[+!+[]]]+[])[+!+[]+[+!+[]]]+(!![]+[])[!+[]+!+[]+!+[]]]](!+[]+!+[]+!+[]+[!+[]+!+[]])+(![]+[])[+!+[]]+(![]+[])[!+[]+!+[]])()([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]][([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([][[]]+[])[+!+[]]+(![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+[]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+(!![]+[])[+!+[]]]((!![]+[])[+!+[]]+(!![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+([][[]]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+!+[]]+([]+[])[(![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([][[]]+[])[+!+[]]+(!![]+[])[+[]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+(![]+[])[!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+(!![]+[])[+!+[]]]()[+!+[]+[!+[]+!+[]]]+((![]+[])[+!+[]]+(![]+[])[!+[]+!+[]]+(!![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+!+[]]+(!![]+[])[+[]]+[+!+[]]+[!+[]+!+[]+!+[]+!+[]+!+[]+!+[]]+[!+[]+!+[]+!+[]+!+[]]+(!![]+[])[+[]]+[!+[]+!+[]+!+[]+!+[]+!+[]]+[+[]]+(!![]+[])[+[]]+[!+[]+!+[]+!+[]+!+[]]+[!+[]+!+[]]+(!![]+[])[+[]]+[+!+[]]+[+!+[]]+[+[]]+(!![]+[])[!+[]+!+[]+!+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[!+[]+!+[]]+(!![]+[])[+[]]+[+!+[]]+[!+[]+!+[]+!+[]+!+[]+!+[]]+[!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]]+(!![]+[])[+[]]+[!+[]+!+[]+!+[]+!+[]]+[+[]]+(!![]+[])[+[]]+[+!+[]]+[!+[]+!+[]]+[!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]]+(!![]+[])[+[]]+[+!+[]]+[!+[]+!+[]+!+[]+!+[]+!+[]]+[!+[]+!+[]+!+[]+!+[]+!+[]+!+[]+!+[]]+(!![]+[])[+!+[]]+(![]+[])[!+[]+!+[]]+([][[]]+[])[!+[]+!+[]]+(!![]+[])[+[]]+[!+[]+!+[]+!+[]+!+[]]+[!+[]+!+[]]+(!![]+[])[+[]]+[!+[]+!+[]+!+[]+!+[]+!+[]]+[+!+[]])[(![]+[])[!+[]+!+[]+!+[]]+(+(!+[]+!+[]+[+!+[]]+[+!+[]]))[(!![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([]+[])[([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([][[]]+[])[+!+[]]+(![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+[]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+(!![]+[])[+!+[]]][([][[]]+[])[+!+[]]+(![]+[])[+!+[]]+((+[])[([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([][[]]+[])[+!+[]]+(![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+[]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+(!![]+[])[+!+[]]]+[])[+!+[]+[+!+[]]]+(!![]+[])[!+[]+!+[]+!+[]]]](!+[]+!+[]+!+[]+[+!+[]])[+!+[]]+(![]+[])[!+[]+!+[]]+([![]]+[][[]])[+!+[]+[+[]]]+(!![]+[])[+[]]]((!![]+[])[+[]])[([][(!![]+[])[!+[]+!+[]+!+[]]+([][[]]+[])[+!+[]]+(!![]+[])[+[]]+(!![]+[])[+!+[]]+([![]]+[][[]])[+!+[]+[+[]]]+(!![]+[])[!+[]+!+[]+!+[]]+(![]+[])[!+[]+!+[]+!+[]]]()+[])[!+[]+!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([![]]+[][[]])[+!+[]+[+[]]]+([][[]]+[])[+!+[]]](([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]][([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([][[]]+[])[+!+[]]+(![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+[]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+(!![]+[])[+!+[]]]((!![]+[])[+!+[]]+(!![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+([][[]]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+!+[]]+(![]+[+[]])[([![]]+[][[]])[+!+[]+[+[]]]+(!![]+[])[+[]]+(![]+[])[+!+[]]+(![]+[])[!+[]+!+[]]+([![]]+[][[]])[+!+[]+[+[]]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(![]+[])[!+[]+!+[]+!+[]]]()[+!+[]+[+[]]]+![]+(![]+[+[]])[([![]]+[][[]])[+!+[]+[+[]]]+(!![]+[])[+[]]+(![]+[])[+!+[]]+(![]+[])[!+[]+!+[]]+([![]]+[][[]])[+!+[]+[+[]]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(![]+[])[!+[]+!+[]+!+[]]]()[+!+[]+[+[]]])()[([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([][[]]+[])[+!+[]]+(![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+[]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+(!![]+[])[+!+[]]]((![]+[+[]])[([![]]+[][[]])[+!+[]+[+[]]]+(!![]+[])[+[]]+(![]+[])[+!+[]]+(![]+[])[!+[]+!+[]]+([![]]+[][[]])[+!+[]+[+[]]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(![]+[])[!+[]+!+[]+!+[]]]()[+!+[]+[+[]]])+[])[+!+[]])+([]+[])[(![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+([][[]]+[])[+!+[]]+(!![]+[])[+[]]+([][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+(![]+[])[!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+(![]+[])[!+[]+!+[]]+(![]+[])[+!+[]]+(!![]+[])[+[]]])[+!+[]+[+[]]]+(!![]+[])[+!+[]]]()[+!+[]+[!+[]+!+[]]])())
</script>
</html>

什么?你不信这可以输出Hello World?那么你可以将其复制下来,放到HTML文件中,再打开试试吧!

为什么?

为什么我们可以仅使用这6个字符来编写这些奇奇怪怪的JavaScript代码?这完全是由于JavaScript独特的类型系统和转换机制。

上面的6个字符可以分为三类:

  • [,]:用于创建数组
  • !,+:对数组执行一些操作
  • (,):对操作进行分组

基础原理

  • []可以用来创建数组,而![]则可以返回false
  • 预定义的规则:2 + true,会转化为2 + 1,最后得到3
  • 预定义的规则:2 + "2",会转化为2 + "2",最后得到"22"

提取字母:![]可以获取false,![] + []那可以获取"false"字符串,那么我们就可以通过下标获取其中的字母,比如:(![] + [])[1]可以获取false字符串中第二位的字母a

提取数字:![]可以获取false,由于+false可以获取0,所以+![]就可以获取到0;由于+true可以获取1,所以+!![]就可以获取到1。这样依靠运算就可以获取更多其他数字

好了,有了这些基础基础知识之后,对于这个神奇的答案知道是怎么来的了吧?

本文首发:仅用六个字符来完成Hello World,你能做到吗?,转载请注明该文章链接

参考资料

欢迎关注我的公众号:程序猿DD,获得独家整理的免费学习资源助力你的Java学习之路!另每周赠书不停哦~

仅用六种字符来完成Hello World,你能做到吗?的更多相关文章

  1. 一篇文章详解python的字符编码问题

    一:什么是编码 将明文转换为计算机可以识别的编码文本称为“编码”.反之从计算机可识别的编码文本转回为明文为“解码”. 那么什么是明文呢,首先我们从一段信息说起,消息以人们可以理解,易懂的表示存在,我们 ...

  2. Python全栈开发之路 【第三篇】:Python基础之字符编码和文件操作

    本节内容 一.三元运算 三元运算又称三目运算,是对简单的条件语句的简写,如: 简单条件语句: if 条件成立: val = 1 else: val = 2 改成三元运算: val = 1 if 条件成 ...

  3. Python2.7字符编码详解

    目录 Python2.7字符编码详解 声明 一. 字符编码基础 1.1 抽象字符清单(ACR) 1.2 已编码字符集(CCS) 1.3 字符编码格式(CEF) 1.3.1 ASCII(初创) 1.3. ...

  4. Python字符编码转换

    编码回顾 在备编码相关的课件时,在知乎上看到一段关于Python编码的回答这哥们的这段话说的太对了,搞Python不把编码彻底搞明白,总有一天它会猝不及防坑你一把.不过感觉这哥们的答案并没把编码问题写 ...

  5. Python入门之字符编码

    一.字节编码的基础知识 一.计算机基础知识 #1 我们的程序都是运行在特定的操作系统内,例如window,linux,mac等等#2 运行应用程序,需要要操作系统发出请求,我们双击运行的时候会向操作系 ...

  6. C++ tinyXML的使用和字符编码转换

    转载:http://jetyi.blog.51cto.com/1460128/761708/ 关于tinyxml使用的文档有很多(这篇文章就写的很好),这里仅提一下字符编码的转换问题,如果你不熟悉字符 ...

  7. Java第三阶段学习(三、字符流、转换流)

    一.字节流读取中文时出现的问题: 文件中有中文时,用字节流读取会出现乱码的问题,因为一个中文为两个字节. 二.字符编码表 编码表:其实就是生活中字符和计算机二进制的对应关系表. 1.ascii: 一个 ...

  8. python学习之路 三:字符编码

    本节重点 彻底掌握字符编码之前的转换关系 掌握 python2 vs python3 上编码的区别 掌握 python2 和python3 上bytes,str 的区别 补充知识点:三元运算 ​三元运 ...

  9. js控制input text字符键入/字符长度限制/字母自动大写

    功能: 1.仅允许指定字符键入 2.限制长度 实现代码: <input type="text" style="width: 6em" name=" ...

随机推荐

  1. 多测师讲解python_os模块_高级讲师肖sir

    #os.path.isfile()#:判断当前是否为文件,返回布尔值是文件则True否者Falsea_path='F:\cms搭建.rar' #lesson包b_path=r'D:\bao\kk '# ...

  2. golang常用库:字段参数验证库-validator

    背景 在平常开发中,特别是在web应用开发中,为了验证输入字段的合法性,都会做一些验证操作.比如对用户提交的表单字段进行验证,或者对请求的API接口字段进行验证,验证字段的合法性,保证输入字段值的安全 ...

  3. 发布TrajStat 1.4.4

    发布TrajStat 1.4.4 (MeteoInfo Java版插件),在PSCF和CWT源区分析中增加了依据格点中的气团轨迹条数为权重进行结果处理的功能.之前的仅有按照轨迹节点数目进行权重处理的功 ...

  4. Django的安装和项目的启动

    一.安装(安装最新LTS版): 1.命令行安装 pip install django==1.11.18 -i 源 2.pycharm 安装    二.创建项目 1.命令行创建 下面的命令创建了一个名为 ...

  5. windows.h头文件中改变光标位置的函数——SetConsoleCursorPosition

    COORD 具体为 typedef struct COORD{ short X; short Y; } COORD,*PCOORD;     可以用来记录坐标. #include <iostre ...

  6. 生物信息-McScan(Python-jcvi)共线性画图

    比较基因组学中,共线性的分析的图无疑是最漂亮的. 共线性分析可以很好地解释进化关系和多倍化事件. 本文主要介绍的是唐老师的Python版McScan(jcvi工具包),这个包很强大,但是其功能在官网的 ...

  7. kafka-消费者测试

    1. 在窗口1创建一个producer,topic为test,broker-list为zookeeper集群ip+端口   /usr/local/kafka/bin/kafka-console-pro ...

  8. gin+gorm 用户服务

    package main import ( "fmt" "github.com/gin-gonic/gin" "github.com/jinzhu/g ...

  9. Helium文档10-WebUI自动化-Text识别网页上的任何文本或标签

    前言 Text关键字的作用是识别网页上的文字,在一般UI查找中使用率非常高,但是需要注意,如果网页上有相同的文字,那么只能识别到第一个 入参介绍 以下是Text的源码 有5个如参:后面4个参数是上下左 ...

  10. Fur 是 .NET 5 平台下企业应用开发最佳实践框架。

    Fur 是 .NET 5 平台下企业应用开发最佳实践框架. 立即尝鲜 Fur 是基于最新的 .NET 5 RC2 构建,目的是为了尽早体验新功能,对即将到来的 .NET 5 正式版做出最快的响应. 所 ...