var f = function(o){ return this+":"+o+"::"+(typeof this)+":"+(typeof o) };
f.call( "2", "2" );
// "2:2::object:string"
var f = function(o){ return this+":"+(typeof this)+":"+(typeof o); };
var x = [1,/foo/,"bar",function(){},true,[],{}];
for (var i=0;i<x.length;++i) console.log(f.call(x[i],x[i]));
// "1:object:number"
// "/foo/:object:object"
// "bar:object:string"
// "function () {\n}:function:function"
// "true:object:boolean"
// ":object:object"
// "[object Object]:object:object"
我在Chrome,Firefox和Safari中看到了相同的结果,因此我认为这是按照规范定义的,但是......为什么呢?规范中是在哪里定义的?为什么函数没有呢?