How to get these key in JavaScript object

Question

I have the following object:

var input = {
        "document": {
            "people":[
                {"name":"Harry Potter","age":"18","gender":"Male"},
                {"name":"hermione granger","age":"18","gender":"Female"}
            ]
        }
    }

I do like this :

_.each(result.document[people], function(item){
    console.log(item); 
    //What should I do here ? or I come wrong way ?
});

And in item I get :

{name : 'Harry Potter', age : '18':, gender:'Male'}
{name : 'hermione grange', age : '18':, gender:'Female'}

I would like to get [name,age,gender]. What should I do?

are you looking for values associated to keys name, age and gender? In `_each` try like this, you can get it `console.log([item.name, item.age,item.gender])` — Koti Panga, Nov 14 '14 at 04:37
I want to do dynamically. So I don't want to use '.' to chain inside. — Hikaru Shindo, Nov 14 '14 at 04:42
In the _.each function I put var key = _.keys(item); And I got [[name,age,gender], [name,age,gender], [name,age,gender], ] What should I do more to get only one array ? — Hikaru Shindo, Nov 14 '14 at 04:56
You already asked the exact same question. http://stackoverflow.com/questions/26901971/how-to-get-all-key-in-json-object-javascript Did the other answer not help you? — royhowie, Nov 14 '14 at 04:57
And asked the same question here as well! http://stackoverflow.com/questions/26908285/how-to-get-a-value-from-specificed-key/26908915#26908915 — Gruff Bunny, Nov 14 '14 at 09:34
You really need to understand the difference between `document.people` and `document[people]` and `document['people']`. A real basic JS tutorial should help you out here. — , Nov 15 '14 at 06:35

score 1 · Answer 1 · answered Nov 14 '14 at 05:18

If you think your values are dynamic use a function first

var input = {
    "document": {
        "people":[
            {"name":"Harry Potter","age":"18","gender":"Male"},
            {"name":"hermione granger","age":"18","gender":"Female"}
        ]
    }
}

var func = function (one, two) {
  var array = input[one][two];
  var arr =[];
  for (var i=0; i<array.length; i++){
     arr = Object.keys(array[0]);
  }
 return arr;       
}
func("document", "people"); // will return ["name", "age", "gender"]

score 1 · Answer 2 · answered Nov 14 '14 at 05:58

1

Try this

var s = {name: "raul", age: "22", gender: "Male"}
   var keys = [];
   for(var k in s) keys.push(k);

Here keys array will return your keys ["name", "age", "gender"]

answered Nov 14 '14 at 05:58

Rahul G Nair

1,366
10
11

score 0 · Answer 3 · answered Nov 14 '14 at 04:55

0

Something like this?

_.each(result.document[people], function(item) {
  _.each(item, function(item, key) {
    console.log(key);
 });
});

_.each sends in a second key parameter to the callback function in the case of objects.

answered Nov 14 '14 at 04:55

Dave Ward

59,815
13
117
134

biko · Answer 4 · 2014-11-15T06:31:16.957

0

Here you go.. Final answer. (edited to return keys instead of values as per comment)

_.each(result.document[people], function(item){
    //get keys as numerical array
    var num_arr = [];
    for (var key in item) {
        num_arr.push( key );
    }
    console.log(num_arr); // should return ['name', 'age', 'gender']

});

edited Nov 15 '14 at 06:31

answered Nov 14 '14 at 05:03

biko

510
6
15

I want ['name', 'age', 'gender'] not value T_T. Do you have the others way ? – Hikaru Shindo Nov 14 '14 at 05:34

Jason Chiang · Answer 5 · 2014-11-14T05:49:47.277

OK, Now I know you actually want the name of object, not the value. So I add another code for you. I'm sorry I don't have time to explain now, but this code I wrote does the trick you need.

This shows the name of object:

root_obj=input.document.people[0];
tmp=[];
for(val in root_obj )
{
  tmp.push(val);
}
console.log(tmp);

This shows the value of object:

root_obj=input.document.people;

for(obj in root_obj )
{
  tmp=[];
  for(val in root_obj[obj] )
  {
    tmp.push(root_obj[obj][val]);
  }
  console.log(tmp);
}

How to get these key in JavaScript object

5 Answers5