deeply-nested

Get information about deeply nested keys in JavaScript objects and arrays

Install

$ npm install deeply-nested

Usage

ES Module

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

CommonJS

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

Examples

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

hasKey(obj, key)

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

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

countKey(obj, key)

Returns: Number

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

obj

Type: Object (or Array)

key

Type: String

Example

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

findPaths(obj, key)

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

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'

getValues(obj, key)

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

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