Get all Keys/Array keys in JSON parse Object?

Question

I have sample JSON like this

`{
  values:[{
    "name": "Base Url",
    "url": "https://kubemanagement-prod.kohls.com"
  },
  {
    "name": "Base Url newwww",
    "url": "https://batman.com"
  }]
}`

Currently when I add this paticular JSON to the lodash _.keys gives me the result ["0", "1"] which is basically the index of first and second object 0 and 1.

What I exactly want is to retrieve all the keys of the JSON object including sub object properties as well. In this case ["values","0", "1","name","url"]

Does anyone knows a lodash method or a mechanism to retrieve all the keys given in complex JSON object to nth level?

language : Angular + Typescript

JSON is a textual notation for data exchange. (More here.) If you're dealing with JavaScript source code, and not dealing with a string, you're not dealing with JSON. What you have isn't a "JSON object," it's an array. — T.J. Crowder
– T.J. Crowder, Commented Jul 2, 2019 at 14:12
Possible duplicate of How to get keys (path to) the deepest nested object in a javascript nested object — Onur Arı
– Onur Arı, Commented Jul 2, 2019 at 14:46

Ori Drori · Accepted Answer · 2019-07-03 07:01:22Z

2

This function recursively gets the keys from an objects tree, using _.keys() and _.flatMap() and _.union() to combine lists of keys, and get only the unique values:

const getAllKeys = obj => _.union(
  _.keys(obj),
  _.flatMap(obj, o => _.isObject(o) ? getAllKeys(o) : [])
)

const arr = {"values": [{"name":"Base Url","url":"https://kubemanagement-prod.kohls.com"},{"name":"Base Url newwww","url":"https://batman.com"}]}

const result = getAllKeys(arr)

console.log(result)

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.js"></script>

And the same idea without lodash, using Object.values() and Array.flatMap() to iterate the current object (or array), and Array.concat() and a Set to make the keys unique:

const getAllKeys = obj => [...new Set([].concat(
  Object.keys(obj),
  Object.values(obj).flatMap(o => typeof o === 'object' ? getAllKeys(o) : [])
))]

const arr = {"values": [{"name":"Base Url","url":"https://kubemanagement-prod.kohls.com"},{"name":"Base Url newwww","url":"https://batman.com"}]}

const result = getAllKeys(arr)

console.log(result)

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.js"></script>

Without array indexes:

const getAllKeys = obj => _.union(
  _.isArray(obj) ? [] : _.keys(obj),
  _.flatMap(obj, o => _.isObject(o) ? getAllKeys(o) : [])
)

const arr = {"values": [{"name":"Base Url","url":"https://kubemanagement-prod.kohls.com"},{"name":"Base Url newwww","url":"https://batman.com"}]}

const result = getAllKeys(arr)

console.log(result)

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.js"></script>

edited Jul 3, 2019 at 7:01

answered Jul 2, 2019 at 14:16

Ori Drori

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6 Comments

T.J. Crowder Over a year ago

Looks like the edit fixes the issue I raised, nice!

Selaka Nanayakkara Over a year ago

Would this solution works for any dynamic JSON object with complex structure? Ex: can have arrays inside even.?

Ori Drori Over a year ago

Both solutions handle dynamic structures of objects and arrays.

Selaka Nanayakkara Over a year ago

Sorry for the fustration it works fine.. I have put semicolan accidently... Thanks for the answer.. Marked as correct answer.

Ori Drori Over a year ago

Sure. Added another answer without the indexes.

|

T.J. Crowder · Accepted Answer · 2019-07-02 14:48:11Z

You don't need lodash for this, Object.keys is sufficient. You just write a recursive function, writing to a Set, perhaps converting to array when you're done:

const array = [
  {
    "name": "Base Url",
    "url": "https://kubemanagement-prod.kohls.com"
  },
  {
    "name": "Base Url newwww",
    "url": "https://batman.com"
  }
];

function addAll(set, entries) {
    for (const entry of entries) {
        set.add(entry);
    }
    return set;
}

function allKeys(obj/*: object|array*/, keys/*: Set<string>*/ = new Set()) {
    addAll(keys, Object.keys(obj));
    for (const entry of Object.values(obj)) {
        if (entry && typeof entry === "object") {
            allKeys(entry, keys);
        }
    }
    return keys;
}

console.log([...allKeys(array)]);

Or using the structure in your edit:

const array = {
  values:[{
    "name": "Base Url",
    "url": "https://kubemanagement-prod.kohls.com"
  },
  {
    "name": "Base Url newwww",
    "url": "https://batman.com"
  }]
}

function addAll(set, entries) {
    for (const entry of entries) {
        set.add(entry);
    }
    return set;
}

function allKeys(obj/*: object|array*/, keys/*: Set<string>*/ = new Set()) {
    addAll(keys, Object.keys(obj));
    for (const entry of Object.values(obj)) {
        if (entry && typeof entry === "object") {
            allKeys(entry, keys);
        }
    }
    return keys;
}

console.log([...allKeys(array)]);

weegee · Accepted Answer · 2019-07-02 14:59:19Z

1

How about

const arr = {"values": [{"name":"Base Url","url":"https://kubemanagement-prod.kohls.com"},{"name":"Base Url newwww","url":"https://batman.com"}]}

let result1 = Object.keys(arr) // get the object keys which is "values"
let result2 = Object.keys(arr[result1]); // get the keys of the object name "0,1" here
let result3 = Object.keys(arr[result1][0]); // get property names of one object "name and url" here
let resutltant = result1.concat(result2, result3) // "merge array"
console.log(resutltant)

Assuming that your object properties names will remain constant

answered Jul 2, 2019 at 14:59

weegee

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Comments

silvelo · Accepted Answer · 2019-07-02 15:00:38Z

-1

If you use typescript why don't use Object.entries or Object.values to do that?

You need to add to tsconfig the next line:

lib: [ ...... "es2018", ]

answered Jul 2, 2019 at 15:00

silvelo

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