Merge pull request #1701 from cchandurkar/patch-1

Update takeWhile.md
This commit is contained in:
Angelos Chalaris
2020-11-29 11:23:24 +02:00
committed by GitHub

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@ -3,19 +3,19 @@ title: takeWhile
tags: array,intermediate
---
Removes elements in an array until the passed function returns `true`.
Removes elements in an array until the passed function returns `false`.
Returns the removed elements.
- Loop through the array, using a `for...of` loop over `Array.prototype.entries()` until the returned value from the function is `true`.
- Loop through the array, using a `for...of` loop over `Array.prototype.entries()` until the returned value from the function is `false`.
- Return the removed elements, using `Array.prototype.slice()`.
```js
const takeWhile = (arr, func) => {
for (const [i, val] of arr.entries()) if (func(val)) return arr.slice(0, i);
for (const [i, val] of arr.entries()) if (!func(val)) return arr.slice(0, i);
return arr;
};
```
```js
takeWhile([1, 2, 3, 4], n => n >= 3); // [1, 2]
takeWhile([1, 2, 3, 4], n => n < 3); // [1, 2]
```