20 lines
595 B
Markdown
20 lines
595 B
Markdown
### flattenDepth
|
|
|
|
Flattens an array up to the specified depth.
|
|
|
|
Use recursion, decrementing `depth` by 1 for each level of depth.
|
|
Use `Array.reduce()` and `Array.concat()` to merge elements or arrays.
|
|
Base case, for `depth` equal to `1` stops recursion.
|
|
Omit the second element, `depth` to flatten only to a depth of `1` (single flatten).
|
|
|
|
```js
|
|
const flattenDepth = (arr, depth = 1) =>
|
|
depth != 1
|
|
? arr.reduce((a, v) => a.concat(Array.isArray(v) ? flattenDepth(v, depth - 1) : v), [])
|
|
: arr.reduce((a, v) => a.concat(v), []);
|
|
```
|
|
|
|
```js
|
|
flattenDepth([1, [2], 3, 4]); // [1,2,3,4]
|
|
```
|