当我做
for (var i in window) console.log(window[i])
当我对“数学”对象做同样的事情时,我什么也没有.
typeof "window" == typeof "Math"
返回TRUE,所以我没有看到为什么我的循环不起作用的原因.
很奇怪,就像我直接写Math [E]我得到常数E的值.
UPDATE
谢谢.所有的答案都是有帮助的,并提供了我想要的.我高涨了大部分.
解决方法
并非所有对象属性都是可迭代的.您只能在for..in循环中获得可迭代的属性.
由于窗口的大部分属性(恰好是全局对象)都是用户定义的全局变量,因此它们是可列举的.
在现代JavaScript引擎中,您可以使用Object.getOwnPropertyNames(obj)来获取所有属性,包括枚举和非可序列化：
>>> Object.getOwnPropertyNames(Math) ["toSource","abs","acos","asin","atan","atan2","ceil","cos","exp","floor","log","max","min","pow","random","round","sin","sqrt","tan","E","LOG2E","LOG10E","LN2","LN10","PI","SQRT2","SQRT1_2"]
详见Is it possible to get the non-enumerable inherited property names of an object?.
