Get a list of objects at each nested level

Question

{
    "John Doe": {
        "Age": 18,
        "Gender": "M"
    },
    "Jane Doe": {
        "Age": 16,
        "Gender": "F"
    },
    "Steve Appleseed":{
        "Age": 21,
        "Gender": "M"
    }
}

Using JavaScript, how do I get an array

var names = ["John Doe", "Jane Doe", "Steve Appleseed"];

If it helps, I'm using Firebase with a JavaScript and jQuery PWA, and I need a list of all the names of objects at a nesting particular level.

So then later, to get John's age, I would use: json[names[0]]["Age"]; json being the name of the root object. — , May 19 '17 at 08:50

Rory McCrossan · Accepted Answer · 2017-05-19T08:56:24.807

4

Firstly note that this has nothing to do with JSON. What you have is an object. Therefore Object.keys will do what you require:

var obj = {
  "John Doe": {
    "Age": 18,
    "Gender": "M"
  },
  "Jane Doe": {
    "Age": 16,
    "Gender": "F"
  },
  "Steve Appleseed": {
    "Age": 21,
    "Gender": "M"
  }
}

var keys = Object.keys(obj);
console.log(keys);

console.log(obj[keys[0]]["Age"]); // John Doe's age

edited May 19 '17 at 08:56

answered May 19 '17 at 08:51

Rory McCrossan

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You're missing a semicolon on the `obj` initialization. Should be `var obj = {...};` – nick zoum May 19 '17 at 08:53

score 1 · Answer 2 · answered May 19 '17 at 08:52

You can use Object.keys(obj)

For more detail, you can see here

var obj = {
    "John Doe": {
        "Age": 18,
        "Gender": "M"
    },
    "Jane Doe": {
        "Age": 16,
        "Gender": "F"
    },
    "Steve Appleseed":{
        "Age": 21,
        "Gender": "M"
    }
};

var result = Object.keys(obj);

console.log(result);

score 0 · Answer 3 · answered May 19 '17 at 08:52

try this

var obj = {
    "John Doe": {
        "Age": 18,
        "Gender": "M"
    },
    "Jane Doe": {
        "Age": 16,
        "Gender": "F"
    },
    "Steve Appleseed":{
        "Age": 21,
        "Gender": "M"
    }
}

    console.log(Object.keys(obj))

score 0 · Answer 4 · answered May 19 '17 at 08:53

You can use object.keys(); for more information you can check https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys

t = {
    "John Doe": {
        "Age": 18,
        "Gender": "M"
    },
    "Jane Doe": {
        "Age": 16,
        "Gender": "F"
    },
    "Steve Appleseed":{
        "Age": 21,
        "Gender": "M"
    }
}

Object.keys(t);

Get a list of objects at each nested level

4 Answers4