[//]: # "The code structure for the repo: https://pauloe-me.medium.com/typescript-npm-package-publishing-a-beginners-guide-40b95908e69c"

deeply-nested !deeply-nested

> Get information about deeply nested keys in JavaScript objects and arrays

Install

``
$ npm install deeply-nested
`

Usage

$3

`js
import { countKey, hasKey, findPaths, getValues } from "deeply-nested";
`

$3

`js
const { countKey, hasKey, findPaths, getValues } = require("deeply-nested");
`

Examples

`js
import { countKey, hasKey, findPaths, getValues } from "deeply-nested";

const deeplyNestedObj = {
a: {
b: {
c: {
d: {
e: "e",
f: "f",
},
},
},
G: undefined,
aFunction: () => {
return true;
},
},
d: {
e: {
f: "F",
},
},
e: "Eeee",
};

// hasKey

hasKey(deeplyNestedObj, "a");
// => true

hasKey(deeplyNestedObj, "x");
// => false

// countKey

countKey(deeplyNestedObj, "a");
// => 1

countKey(deeplyNestedObj, "e");
// => 3

countKey(deeplyNestedObj, "x");
// => 0

// findPaths

findPaths(deeplyNestedObj, "a");
// => [ 'a' ]

findPaths(deeplyNestedObj, "e");
// => [ 'e', 'a.b.c.d.e', 'd.e' ]

findPaths(deeplyNestedObj, "x");
// => []

// getValues

getValues(deeplyNestedObj, "b");
// => [ { c: { d: [Object] } } ]

getValues(deeplyNestedObj, "e");
// => [ 'Eeee', 'e', { f: 'F' } ]

getValues(deeplyNestedObj, "G");
// => [ undefined ]

getValues(deeplyNestedObj, "aFunction");
// => [ [Function: aFunction] ]

getValues(deeplyNestedObj, "aFunction")[0]();
// => true
`

---

APIs

$3

Returns: Boolean

Returns true or false depending on whether the key is found in the nested object.

#### obj

Type: Object (or Array)

#### key

Type: String

#### Example

`js
hasKey(obj, "id"); // => true
`

$3

Returns: Number

Returns the number of occurrences of the key in the nested object.

#### obj

Type: Object (or Array)

#### key

Type: String

#### Example

`js
countKey(obj, "name"); // => 3
`

$3

Returns: String[]

Returns an array of all the paths where the key occurs in the nested object, as dot-delimited strings (e.g., 'a.b.c.d.e').

#### obj

Type: Object (or Array)

#### key

Type: String

#### Example

`js
findPaths(obj, "email");
// => [ 'employee.addresses[0].email', 'employee.addresses[1].email' ]

// The paths are lodash.get compatible:
import _ from "lodash";

const path = findPaths(obj, "provider");
// => [ 'user.profile.addresses[0].emails[0].provider'];

_.get(obj, path[0]);
// => 'gmail'
`

$3

Returns: Any[]

Returns an array of all the values corresponding to the key's occurrences in the nested object.

#### obj

Type: Object (or Array)

#### key

Type: String

#### Example

`js
getValues(obj, "age"); // => [ 25, 30, 45 ]
``

Additional Resources

This library implementation is based on depth-first search algorithms I originally shared in my blog posts for confirming the existence of nested keys and finding their paths in JavaScript:

- Check if Key Exists in Deeply Nested Object or Array of Objects
- Find Path of Key In Deeply Nested Object or Array

---

License

MIT © Talha Awan