35 lines
1.1 KiB
Markdown
35 lines
1.1 KiB
Markdown
---
|
|
title: unflattenObject
|
|
tags: object,advanced
|
|
---
|
|
|
|
Unflatten an object with the paths for keys.
|
|
|
|
- Use nested `Array.prototype.reduce()` to convert the flat path to a leaf node.
|
|
- Use `String.prototype.split('.')` to split each key with a dot delimiter and `Array.prototype.reduce()` to add objects against the keys.
|
|
- If the current accumulator already contains a value against a particular key, return its value as the next accumulator.
|
|
- Otherwise, add the appropriate key-value pair to the accumulator object and return the value as the accumulator.
|
|
|
|
```js
|
|
const unflattenObject = obj =>
|
|
Object.keys(obj).reduce((res, k) => {
|
|
k.split('.').reduce(
|
|
(acc, e, i, keys) =>
|
|
acc[e] ||
|
|
(acc[e] = isNaN(Number(keys[i + 1]))
|
|
? keys.length - 1 === i
|
|
? obj[k]
|
|
: {}
|
|
: []),
|
|
res
|
|
);
|
|
return res;
|
|
}, {});
|
|
```
|
|
|
|
```js
|
|
unflattenObject({ 'a.b.c': 1, d: 1 }); // { a: { b: { c: 1 } }, d: 1 }
|
|
unflattenObject({ 'a.b': 1, 'a.c': 2, d: 3 }); // { a: { b: 1, c: 2 }, d: 3 }
|
|
unflattenObject({ 'a.b.0': 8, d: 3 }); // { a: { b: [ 8 ] }, d: 3 }
|
|
```
|