这个神奇的JavaScript代码如何工作? [英] How does this magic JavaScript code work?

查看：44
本文介绍了这个神奇的JavaScript代码如何工作?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

这是一小段JavaScript代码，可提醒"Hello world":

This is a small piece of JavaScript code that alerts "Hello world":

ﾟωﾟﾉ=/｀ｍ´）ﾉ~┻━┻//*´∇｀*/['_'];o=(ﾟｰﾟ)=_=3;c=(ﾟΘﾟ)=(ﾟｰﾟ)-(ﾟｰﾟ);(ﾟДﾟ)=(ﾟΘﾟ)=(o^_^o)/(o^_^o);(ﾟДﾟ)={ﾟΘﾟ:'_',ﾟωﾟﾉ:((ﾟωﾟﾉ==3)+'_')[ﾟΘﾟ],ﾟｰﾟﾉ:(ﾟωﾟﾉ+'_')[o^_^o-(ﾟΘﾟ)],ﾟДﾟﾉ:((ﾟｰﾟ==3)+'_')[ﾟｰﾟ]};(ﾟДﾟ)[ﾟΘﾟ]=((ﾟωﾟﾉ==3)+'_')[c^_^o];(ﾟДﾟ)['c']=((ﾟДﾟ)+'_')[(ﾟｰﾟ)+(ﾟｰﾟ)-(ﾟΘﾟ)];(ﾟДﾟ)['o']=((ﾟДﾟ)+'_')[ﾟΘﾟ];(ﾟoﾟ)=(ﾟДﾟ)['c']+(ﾟДﾟ)['o']+(ﾟωﾟﾉ+'_')[ﾟΘﾟ]+((ﾟωﾟﾉ==3)+'_')[ﾟｰﾟ]+((ﾟДﾟ)+'_')[(ﾟｰﾟ)+(ﾟｰﾟ)]+((ﾟｰﾟ==3)+'_')[ﾟΘﾟ]+((ﾟｰﾟ==3)+'_')[(ﾟｰﾟ)-(ﾟΘﾟ)]+(ﾟДﾟ)['c']+((ﾟДﾟ)+'_')[(ﾟｰﾟ)+(ﾟｰﾟ)]+(ﾟДﾟ)['o']+((ﾟｰﾟ==3)+'_')[ﾟΘﾟ];(ﾟДﾟ)['_']=(o^_^o)[ﾟoﾟ][ﾟoﾟ];(ﾟεﾟ)=((ﾟｰﾟ==3)+'_')[ﾟΘﾟ]+(ﾟДﾟ).ﾟДﾟﾉ+((ﾟДﾟ)+'_')[(ﾟｰﾟ)+(ﾟｰﾟ)]+((ﾟｰﾟ==3)+'_')[o^_^o-ﾟΘﾟ]+((ﾟｰﾟ==3)+'_')[ﾟΘﾟ]+(ﾟωﾟﾉ+'_')[ﾟΘﾟ];(ﾟｰﾟ)+=(ﾟΘﾟ);(ﾟДﾟ)[ﾟεﾟ]='\\';(ﾟДﾟ).ﾟΘﾟﾉ=(ﾟДﾟ+ﾟｰﾟ)[o^_^o-(ﾟΘﾟ)];(oﾟｰﾟo)=(ﾟωﾟﾉ+'_')[c^_^o];(ﾟДﾟ)[ﾟoﾟ]='\"';(ﾟДﾟ)['_']((ﾟДﾟ)['_'](ﾟεﾟ+(ﾟДﾟ)[ﾟoﾟ]+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+(ﾟｰﾟ)+(ﾟΘﾟ)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+(ﾟｰﾟ)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+(ﾟｰﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((o^_^o)+(o^_^o))+((o^_^o)-(ﾟΘﾟ))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((o^_^o)+(o^_^o))+(ﾟｰﾟ)+(ﾟДﾟ)[ﾟεﾟ]+((ﾟｰﾟ)+(ﾟΘﾟ))+(c^_^o)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟｰﾟ)+((o^_^o)-(ﾟΘﾟ))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+(ﾟΘﾟ)+(c^_^o)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+(ﾟｰﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+(ﾟｰﾟ)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+(ﾟｰﾟ)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+((ﾟｰﾟ)+(o^_^o))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟｰﾟ)+(c^_^o)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((o^_^o)-(ﾟΘﾟ))+((ﾟｰﾟ)+(o^_^o))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+((ﾟｰﾟ)+(o^_^o))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((o^_^o)+(o^_^o))+((o^_^o)-(ﾟΘﾟ))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+(ﾟｰﾟ)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+(ﾟｰﾟ)+(ﾟｰﾟ)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟｰﾟ)+((o^_^o)-(ﾟΘﾟ))+(ﾟДﾟ)[ﾟεﾟ]+((ﾟｰﾟ)+(ﾟΘﾟ))+(ﾟΘﾟ)+(ﾟДﾟ)[ﾟoﾟ])(ﾟΘﾟ))('_');

好看的版本:

ﾟωﾟﾉ = /｀ｍ´）ﾉ~┻━┻//*´∇｀*/['_'];
o = (ﾟｰﾟ) = _ = 3;
c = (ﾟΘﾟ) = (ﾟｰﾟ) - (ﾟｰﾟ);
(ﾟДﾟ) = (ﾟΘﾟ) = (o^_^o)/(o^_^o);
(ﾟДﾟ) = {
  ﾟΘﾟ:  '_',
  ﾟωﾟﾉ: ((ﾟωﾟﾉ==3)+'_')[ﾟΘﾟ],
  ﾟｰﾟﾉ: (ﾟωﾟﾉ+'_')[o^_^o-(ﾟΘﾟ)],
  ﾟДﾟﾉ: ((ﾟｰﾟ==3)+'_')[ﾟｰﾟ]
};
(ﾟДﾟ)[ﾟΘﾟ] = ((ﾟωﾟﾉ==3)+'_')[c^_^o];
(ﾟДﾟ)['c'] = ((ﾟДﾟ)+'_')[(ﾟｰﾟ)+(ﾟｰﾟ)-(ﾟΘﾟ)];
(ﾟДﾟ)['o'] = ((ﾟДﾟ)+'_')[ﾟΘﾟ];
(ﾟoﾟ)=(ﾟДﾟ)['c'] + (ﾟДﾟ)['o'] + (ﾟωﾟﾉ + '_')[ﾟΘﾟ] + ((ﾟωﾟﾉ==3) + '_')[ﾟｰﾟ] + ((ﾟДﾟ) + '_')[(ﾟｰﾟ) + (ﾟｰﾟ)] + ((ﾟｰﾟ==3) + '_')[ﾟΘﾟ] + ((ﾟｰﾟ==3) + '_')[(ﾟｰﾟ) - (ﾟΘﾟ)] + (ﾟДﾟ)['c'] + ((ﾟДﾟ) + '_')[(ﾟｰﾟ) + (ﾟｰﾟ)] + (ﾟДﾟ)['o'] + ((ﾟｰﾟ==3) + '_')[ﾟΘﾟ];
(ﾟДﾟ)['_'] = (o^_^o)[ﾟoﾟ][ﾟoﾟ];
(ﾟεﾟ) = ((ﾟｰﾟ==3) + '_')[ﾟΘﾟ] + (ﾟДﾟ).ﾟДﾟﾉ + ((ﾟДﾟ) + '_')[(ﾟｰﾟ) + (ﾟｰﾟ)] + ((ﾟｰﾟ==3) + '_')[o^_^o-ﾟΘﾟ] + ((ﾟｰﾟ==3) + '_')[ﾟΘﾟ] + (ﾟωﾟﾉ+'_')[ﾟΘﾟ];
(ﾟｰﾟ) += (ﾟΘﾟ);
(ﾟДﾟ)[ﾟεﾟ] = '\\';
(ﾟДﾟ).ﾟΘﾟﾉ = (ﾟДﾟ+ﾟｰﾟ)[o^_^o-(ﾟΘﾟ)];
(oﾟｰﾟo) = (ﾟωﾟﾉ+'_')[c^_^o];
(ﾟДﾟ)[ﾟoﾟ] = '\"';
(ﾟДﾟ)['_']((ﾟДﾟ)['_'](ﾟεﾟ+(ﾟДﾟ)[ﾟoﾟ]+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+(ﾟｰﾟ)+(ﾟΘﾟ)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+(ﾟｰﾟ)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+(ﾟｰﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((o^_^o)+(o^_^o))+((o^_^o)-(ﾟΘﾟ))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((o^_^o)+(o^_^o))+(ﾟｰﾟ)+(ﾟДﾟ)[ﾟεﾟ]+((ﾟｰﾟ)+(ﾟΘﾟ))+(c^_^o)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟｰﾟ)+((o^_^o)-(ﾟΘﾟ))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+(ﾟΘﾟ)+(c^_^o)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+(ﾟｰﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+(ﾟｰﾟ)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+(ﾟｰﾟ)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+((ﾟｰﾟ)+(o^_^o))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟｰﾟ)+(c^_^o)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((o^_^o)-(ﾟΘﾟ))+((ﾟｰﾟ)+(o^_^o))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+((ﾟｰﾟ)+(o^_^o))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((o^_^o)+(o^_^o))+((o^_^o)-(ﾟΘﾟ))+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+((ﾟｰﾟ)+(ﾟΘﾟ))+(ﾟｰﾟ)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟΘﾟ)+(ﾟｰﾟ)+(ﾟｰﾟ)+(ﾟДﾟ)[ﾟεﾟ]+(ﾟｰﾟ)+((o^_^o)-(ﾟΘﾟ))+(ﾟДﾟ)[ﾟεﾟ]+((ﾟｰﾟ)+(ﾟΘﾟ))+(ﾟΘﾟ)+(ﾟДﾟ)[ﾟoﾟ])(ﾟΘﾟ))('_');

JSFiddle

它是从这里获取的: https://codegolf.stackexchange.com/Questions/23975/obfuscation-challenge/24041#24041

它如何工作?我什至看不到该代码中的 alert .

How does it work? I don't even see the alert in that code.

推荐答案

在仔细阅读代码之前，您必须知道自JavaScript 1.5起

Before looking closer at the code, you have to know that since JavaScript 1.5 identifiers are allowed to contain not just ASCII characters but also Unicode characters.

在这种情况下，这些有趣的序列中的许多仅仅是标识符.通过简单的标识符交换了这些标识符并删除了不必要的注释和括号后，代码如下:

In this case many of these funny sequences are just identifiers. After exchanging these identifiers by simpler identifiers and removing unnecessary comments and parenthesis, the code looks as follows:

a = /｀ｍ´）ﾉ~┻━┻/['_'];
o = b = _ = 3;
c = d = b-b;
e = d = o^_^o/o^_^o;
e = {
  d: '_',
  a: ((a==3)+'_')[d],
  h: (a+'_')[o^_^o-d],
  i: ((b==3)+'_')[b]
};
e[d]   = ((a==3)+'_')[c^_^o];
e['c'] = (e+'_')[b+b-d];
e['o'] = (e+'_')[d];
f      = e['c']+e['o']+(a+'_')[d]+((a==3)+'_')[b]+(e+'_')[b+b]+((b==3)+'_')[d]+((b==3)+'_')[b-d]+e['c']+(e+'_')[b+b]+e['o']+((b==3)+'_')[d];
e['_'] = (o^_^o)[f][f];
g      = ((b==3)+'_')[d]+e.i+(e+'_')[b+b]+((b==3)+'_')[o^_^o-d]+((b==3)+'_')[d]+(a+'_')[d];
b      += d;
e[g]   = '\\';
e.j    = (e+b)[o^_^o-d];
obo    = (a+'_')[c^_^o];
e[f]   = '\"';
e['_'](e['_'](g+e[f]+e[g]+d+b+d+e[g]+d+(b+d)+b+e[g]+d+b+(b+d)+e[g]+d+((o^_^o)+(o^_^o))+((o^_^o)-d)+e[g]+d+((o^_^o)+(o^_^o))+b+e[g]+(b+d)+(c^_^o)+e[g]+b+((o^_^o)-d)+e[g]+d+d+(c^_^o)+e[g]+d+b+(b+d)+e[g]+d+(b+d)+b+e[g]+d+(b+d)+b+e[g]+d+(b+d)+(b+(o^_^o))+e[g]+b+(c^_^o)+e[g]+d+((o^_^o)-d)+(b+(o^_^o))+e[g]+d+(b+d)+(b+(o^_^o))+e[g]+d+((o^_^o)+(o^_^o))+((o^_^o)-d)+e[g]+d+(b+d)+b+e[g]+d+b+b+e[g]+b+((o^_^o)-d)+e[g]+(b+d)+d+e[f])(d))('_');

现在，我们可以一次评估每个语句:

Now we’re able to evaluate each statement at a time:

  • a =/｀ ｍ´)ﾉ〜┻━┻/['_'] 的结果为 a =未定义
  • o = b = _ = 3 为 o ， b 和 _ 分配整数3
  • c = d = b-b 为 c 和 d 分配整数 0
  • e = d = o ^ _ ^ o/o ^ _ ^ o 为 e 和 d 分配整数 1 ( o ^ _ ^ o 的计算结果为3 XOR 3 XOR 3，得出3)
  • e = {d:'_'，a:((a == 3)+'_')[d]，h:(a +'_')[o ^ _ ^ od]，i:(((b == 3)+'_')[b]} 分配 e 对象 {d:'_'，a:'a'，h:'d'，i:'e'}
  • e [d] =((a == 3)+'_')[c ^ _ ^ o] 分配 e [1] 字符串'f'
  • e ['c'] =(e +'_')[b + bd] 分配 e ['c'] 字符串'c'
  • e ['o'] =(e +'_')[d] 分配 e ['o'] 字符串'o'
  • a = /｀ｍ´）ﾉ~┻━┻/['_'] evaluates to a = undefined
  • o = b = _ = 3 assigns o, b, and _ the integer 3
  • c = d = b-b assigns c and d the integer 0
  • e = d = o^_^o/o^_^o assigns e and d the integer 1 (o^_^o evaluates to 3 XOR 3 XOR 3, which yields 3)
  • e = { d: '_', a: ((a==3)+'_')[d], h: (a+'_')[o^_^o-d], i: ((b==3)+'_')[b] } assigns e the object { d: '_', a: 'a', h: 'd', i: 'e' }
  • e[d] = ((a==3)+'_')[c^_^o] assigns e[1] the string 'f'
  • e['c'] = (e+'_')[b+b-d] assigns e['c'] the string 'c'
  • e['o'] = (e+'_')[d] assigns e['o'] the string 'o'

这仅仅是设置，并设置了以下变量:

This was all just the setup and the following variables are set:

a = undefined
b = 3
c = 0
d = 1
e = {
    1: "f",
    a: "a",
    c: "c",
    d: "_",
    h: "d",
    i: "e",
    o: "o"
}

下一条语句是构造某些内容的第一条语句:

The next statement is the first that constructs something:

f = e['c'] +             // => "c"
    e['o'] +             // => "o"
    (a+'_')[d] +         // => "undefined_"[1] = "n"
    ((a==3)+'_')[b] +    // => "false_"[3]     = "s"
    (e+'_')[b+b] +       // => "object_"[6]    = "t"
    ((b==3)+'_')[d] +    // => "true_"[1]      = "r"
    ((b==3)+'_')[b-d] +  // => "true_"[2]      = "s"
    e['c'] +             // => "c"
    (e+'_')[b+b] +       // => "object_"[6]    = "t"
    e['o'] +             // => "o"
    ((b==3)+'_')[d];     // => "true"[1]       = "r"

所以 f ="constructor" .在下一条语句中，此构造函数" 用于检索函数:

So f = "constructor". In the next statement this "constructor" is used to retrieve a function:

e['_'] = (o^_^o)[f][f]

这等效于(3).constructor.constructor ，产生

This is equivalent to (3).constructor.constructor, which yields the function Function, so:

e['_'] = Function

此 Function 函数之所以特别，是因为它可以通过参数传递函数主体代码来动态构造函数:

This Function function is special as one can construct functions dynamically by passing it the function body code via parameter:

f = Function("alert(1)")
// equivalent to
f = function() { alert(1) }

我将跳过接下来的几条语句，只写结果变量和值:

I’ll skip the next few statements and just write the resulting variables and values:

a = undefined
b = 4
c = 0
d = 1
e = {
    1: "f",
    _: Function,
    a: "a",
    c: "c",
    constructor: "\"",
    d: "_",
    h: "d",
    i: "e",
    j: "b",
    o: "o",
    return: "\\"
}
f = "constructor"
obo = "u"

最后一条语句完成了最后的工作:

The last statement does the final work:

e['_'](e['_'](g+e[f]+e[g]+d+b+d+e[g]+d+(b+d)+b+e[g]+d+b+(b+d)+e[g]+d+((o^_^o)+(o^_^o))+((o^_^o)-d)+e[g]+d+((o^_^o)+(o^_^o))+b+e[g]+(b+d)+(c^_^o)+e[g]+b+((o^_^o)-d)+e[g]+d+d+(c^_^o)+e[g]+d+b+(b+d)+e[g]+d+(b+d)+b+e[g]+d+(b+d)+b+e[g]+d+(b+d)+(b+(o^_^o))+e[g]+b+(c^_^o)+e[g]+d+((o^_^o)-d)+(b+(o^_^o))+e[g]+d+(b+d)+(b+(o^_^o))+e[g]+d+((o^_^o)+(o^_^o))+((o^_^o)-d)+e[g]+d+(b+d)+b+e[g]+d+b+b+e[g]+b+((o^_^o)-d)+e[g]+(b+d)+d+e[f])(d))('_');

这等效于:

Function(Function( … )(1))('_')

长表达式生成以下字符串:

The long expression builds the following string:

return"\141\154\145\162\164\50\42\110\145\154\154\157\40\127\157\162\154\144\42\51"

转义的字符串计算为:

alert("Hello World")

此返回代码被传递给 Function ，该函数将创建一个匿名函数，例如:

This return code is passed to Function, which creates an anonymous function like:

function anonymous() {
    return"\141\154\145\162\164\50\42\110\145\154\154\157\40\127\157\162\154\144\42\51";
}

我们知道，这等同于:

function anonymous() {
    return"alert(\"Hello World\")";
}

然后以 1 作为参数执行此函数，该函数返回结果字符串:

This function is then executed with 1 as parameter, which returns the resulting string:

alert("Hello World")

然后将其再次传递给 Function ，这将创建一个新的匿名函数:

This is then passed to Function again, which creates a new anonymous function:

function anonymous() {
    alert("Hello World");
}

最后，还使用'_'作为参数来调用此函数.

Finally, this function is also invoked with '_' as parameter.

这篇关于这个神奇的JavaScript代码如何工作?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！

查看全文
相关文章
前端开发最新文章
热门教程
热门工具
登录 关闭
扫码关注1秒登录
发送“验证码”获取 | 15天全站免登陆