javascript获取json内部值

Question

Let's I have next object

   var o = { "foo" : {"bar" : "omg"} };  

I can get value of key foo using

o["foo"] // return {"bar" : "omg"} 

and I can get value of key bar inside foo using

o["foo"]["bar"]  // return "omg"   

Can I get value of key bar inside foo using brackets [] single time.
Somethong like

o["foo.bar"] // not working(

or

o["foo/bar"] // not working(

Answer 1

It is fairly common to create a getter function to do something like this. From the comment:

I have object o and string 'foo.bar', and i want get "omg".

var getProp = function (theObject, propString) {
    var current = theObject;
    var split = propString.split('.');

    for (var i = 0; i < split.length; i++) {
        if (current.hasOwnProperty(split[i])) {
            current = current[split[i]];
        }
    }

    return current;
};

http://jsfiddle.net/MXu2M/

Note: this is a thrown together example, you'd want to bullet proof and buff it up before dropping it on your site.

Answer 2

不幸的是，您只能使用o["foo"]["bar"]或o.foo.bar

Answer 3

No, you must use o["foo"]["bar"] because it's an object inside another object. If you want to access it with "foo.bar", it means you must create the first object like this:

var o = {"foo.bar": "omg"}

Answer 4

o["foo.bar"] or o["foo/bar"] are not valid for your example. You could use this notation that is cleaner:

var bar = o.foo.bar // bar will contain 'omg'

Answer 5

there is a way, but I'm not sure this is what you asked for:

eval("o.foo.bar");

it is dangerous though, and doesn't use [] , but if what you want is to use a string for accessing any object it works