JavaScript 奇巧淫技
		
  
评级组件
		
  
"★★★★★☆☆☆☆☆".slice(5 - rate, 10 - rate); // 定义一个变量rate是1到5的值

		
  
输出单词
		
  
++[[]][+[]]+[+[]]
		
  
(!(~+[])+{})[--[~+""][+[]]*[~+[]] + ~~!+[]]+({}+[])[[~!+[]]*~+[]]
		
  
([][[]]+[])[+!![]]+([]+{})[!+[]+!![]]

		
  
错误处理的正确姿势
		
  
try {
    something
} catch (e) {
    window.location.href = "http://stackoverflow.com/search?q=[js]+" + e.message
}

		
  
所有元素边框加色
		
  
[].forEach.call($$("*"), a => {a.style.outline="1px solid #"+(~~(Math.random()*(1<<24))).toString(16)})

		
  
随机字符串
		
  
Math.random().toString(16).substring(2) // 13位
Math.random().toString(36).substring(2) // 11位

		
  
匿名函数自执行
		
  
(function(){}());
(function(){})();
[function(){}()];

~function(){}();
!function(){}();
+function(){}();
-function(){}();

delete function(){}();
typeof function(){}();
void function(){}();
new function(){}();
new function(){};

var f = function(){}();

1, function(){}();
1 ^ function(){}();
1 > function(){}();
// ...

		
  
取整
		
  
~~2.33
2.33 | 0
2.33 >> 0

		
  
货币格式化 1,234,567,890
		
  
'1234567890'.replace(/\B(?=(\d{3})+(?!\d))/g, ',')
		
  
'1234567890'.split('').reverse().reduce((prev, next, index) => (index % 3 ? next : next + ',') + prev)

		
  
两个整数交换数值
		
  
var a=1,b=2;
a += b;
b = a - b;
a -= b; // 缺点也很明显，整型数据溢出，对于32位字符最大表示数字是2147483647
		
  
a ^= b;
b ^= a;
a ^= b; // 位操作

		
  
数组特性
		
  
[...new Set([1, "1", 2, 1, 1, 3])] // 去重
		
  
Array(6).fill(8) // 重复数组
		
  
var numbers = [5, 458 , 120 , -215 , 228 , 400 , 122205, -85411];
Math.max.apply(Math, numbers)
Math.max(...numbers) // 数组最大值
		
  
Array.prototype.slice.call(arguments)
Array.from(arguments) // 将argruments对象转换成数组
		
  
一个数组中找到一个数 find([0,1,2,3,4,5], 2)
function find (x, y) {
  for (let i = 0; i < x.length; i++) if (x[i] == y) return i;
}
		
  
const find = (g => g(g)) (f =>
  (next => (x, y, i = 0) =>
    i >= x.length ?  null :
      x[i] == y ? i :
        next(x, y, i+1))((...args) => f(f)(...args)))

		
  
数字运算
		
  
parseInt(0.0000008)  // 8
		
  
0.1 + 0.2  // 0.30000000000000004, 使用 ES6 的 Number.EPSILON 来更正

		
  
参考
		
  
 
   
 https://github.com/jawil/blog/issues/24 
 
   
 https://en.wikipedia.org/wiki/JSFuck 
 
   
 https://esolangs.org/wiki/JSFuck 
 
   
 http://patriciopalladino.com/blog/2012/08/09/non-alphanumeric-javascript.html 
 
   
 https://raw.githubusercontent.com/aemkei/jsfuck/master/jsfuck.js