Access to complex javascript object properties,

Question

I have that object sample pages:

{
"page_1":
   {
     "stats":
       {
         "stat_1": 20,
         "stat_2": 40
       }
     "ahkam":
       {
         //Staff
       }
   }
"page_2":
   {
      //staff
   }
}

How can i get access to the value of stat_2? I used that expression but i don't know why it does not work:

Object.keys(pages["page_1"].stats)["stat_1"]

What's with the `Object.keys`? Why not just `pages.page_1.stats.stat_1`? — Thilo, Jul 20 '13 at 09:27
page_x is a key, I need to parse the "pages" object through it — Houssam Badri, Jul 20 '13 at 09:29

rid · Accepted Answer · 2013-07-20T09:44:44.317

2

This is a visualisation of the data:

enter image description here

Therefore, to get there, you'd use:

var stat = pages.page_1.stats.stat_2;

If "page_1" is dynamic, then you can use the bracket notation (also known as the subscript notation):

var key = 'page_' + x;
var stat = pages[key].stats.stat_2;

If "stat_2" is also dynamic, then again, you can use the same notation:

var pageKey = 'page_' + x;
var statKey = 'stat_' + n;
var stat = pages[pageKey].stats[statKey];

Or you could use this notation for the whole expression:

var stat = pages[pageKey]['stats'][statKey];

Basically, a.b.c is equivalent to a['b']['c'], where in this case 'b' and 'c' are string literals, but can be any expression.

edited Jul 20 '13 at 09:44

answered Jul 20 '13 at 09:28

rid

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page_1 is a variable, it is the key of parsing the object, it is in string format – Houssam Badri Jul 20 '13 at 09:33
@HoussemBdr, alright, then use the subscript notation. Example updated. – rid Jul 20 '13 at 09:33
FYI, it's called *bracket notation*. http://www.ecma-international.org/ecma-262/5.1/#sec-11.2.1 – Felix Kling Jul 20 '13 at 09:39
1

@FelixKling, it has many names, apparently. Crockford uses the term ["subscript notation"](http://javascript.crockford.com/survey.html). So if someone is looking it up, they should probably try both versions. Anyway, answer updated with both versions, thanks for the link. – rid Jul 20 '13 at 09:40

score 0 · Answer 2 · answered Jul 20 '13 at 09:27

0

as

obj = { 
       field1: {
                stat1: "string";
       }
}


obj.field1.stat1

answered Jul 20 '13 at 09:27

steo

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score 0 · Answer 3 · answered Jul 20 '13 at 09:29

0

is this not enough, Assign that object to var Page = {....}

  Page.page_1.stats.stat_1

answered Jul 20 '13 at 09:29

Sarath

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Access to complex javascript object properties,

3 Answers3