30-seconds-of-code/snippets/deepGet.md

title, tags

title	tags
deepGet	object,intermediate

Returns the target value in a nested JSON object, based on the keys array.

Compare the keys you want in the nested JSON object as an Array. Use Array.prototype.reduce() to get value from nested JSON object one by one. If the key exists in object, return target value, otherwise, return null.

---
title: deepGet
tags: object,intermediate
---

Returns the target value in a nested JSON object, based on the `keys` array.

Compare the keys you want in the nested JSON object as an `Array`.
Use `Array.prototype.reduce()` to get value from nested JSON object one by one. 
If the key exists in object, return target value, otherwise, return `null`.

```js
const deepGet = (obj, keys) =>
  keys.reduce(
    (xs, x) => (xs && xs[x] !== null && xs[x] !== undefined ? xs[x] : null),
    obj
  );

let index = 2;
const data = {
  foo: {
    foz: [1, 2, 3],
    bar: {
      baz: ['a', 'b', 'c']
    }
  },
  name: null,
  isDark: false
};
deepGet(data, ['foo', 'foz', index]); // get 3
deepGet(data, ['foo', 'bar', 'baz', 8, 'foz']); // undefined
deepGet(data, ['name']); // null
deepGet(data, ['isDark']); // false

```js
let index = 2;
const data = {
  foo: {
    foz: [1, 2, 3],
    bar: {
      baz: ['a', 'b', 'c']
    }
  }
};
deepGet(data, ['foo', 'foz', index]); // get 3
deepGet(data, ['foo', 'bar', 'baz', 8, 'foz']); // null