Coffeescript / Javascript - 为什么对象属性未定义？

Question

I have this function that I'm using it in a Rails 3.1 project:

setPosition: (object) ->
    console.log object
    console.log object.width
    object["position"] = [500, 50] 
    this

The console.log object gives

Object
    height: 600
    position: Array[2]
    title: "Banner for Creative"
    width: 160
    __proto__: Object

but console.log object.width is undefined. Why ?

Answer 1

I answered a similar question just a couple of days ago: https://stackoverflow.com/a/8299394/66226

Basically, console.log has some asynchronous behaviors (in some environments). So when you pass in a reference to an object, that object is stringified later—whereas object.width is undefined right now.

If you do

console.log object.toString()

then you should get more consistent results (though less pretty ones).

Edit: Or better yet,

console.log JSON.stringify(object)

See comments below.