为什么参数对象未在控制台中显示其方法

Question

Take a look at this code:

var args;
function foo(){
  args = arguments;
}

foo();

console.log(args); // []
args.callee(); // foo

how come I'm not able to see any property or method of arguments object in console yet able to call callee method ?

Answer 1

You are not passing foo any arguments. Also, The callee property is "non-enumerable".

Answer 2

_{Disclaimer: this assumes you're using the Chrome or Firebug consoles, there is no standard, so custom consoles might do funky things.}

Because you used console.log which displays array-like* objects differently from "plain" objects. If you want to see the properties on the object, use console.dir .

_{* to be array-like the object has to have a length property and splice function, or a number of other niche conditions.}