27 lines
884 B
Markdown
27 lines
884 B
Markdown
---
|
|
title: pullAtIndex
|
|
tags: array,advanced
|
|
---
|
|
|
|
Mutates the original array to filter out the values at the specified indexes.
|
|
|
|
Use `Array.prototype.filter()` and `Array.prototype.includes()` to pull out the values that are not needed.
|
|
Use `Array.prototype.length = 0` to mutate the passed in an array by resetting it's length to zero and `Array.prototype.push()` to re-populate it with only the pulled values.
|
|
Use `Array.prototype.push()` to keep track of pulled values
|
|
|
|
```js
|
|
const pullAtIndex = (arr, pullArr) => {
|
|
let removed = [];
|
|
let pulled = arr
|
|
.map((v, i) => (pullArr.includes(i) ? removed.push(v) : v))
|
|
.filter((v, i) => !pullArr.includes(i));
|
|
arr.length = 0;
|
|
pulled.forEach(v => arr.push(v));
|
|
return removed;
|
|
};
|
|
```
|
|
|
|
```js
|
|
let myArray = ['a', 'b', 'c', 'd'];
|
|
let pulled = pullAtIndex(myArray, [1, 3]); // myArray = [ 'a', 'c' ] , pulled = [ 'b', 'd' ]
|
|
``` |