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30-seconds-of-code/snippets/takeWhile.md
2018-05-17 17:17:38 +04:00

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### takeWhile
Removes elements in an array until the passed function returns `true`. Returns the removed elements.
Loop through the array, using a `for...of` loop over `Array.entries()` until the returned value from the function is `true`.
Return the removed elements, using `Array.slice()`.
```js
const takeWhile = (arr, func) => {
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]
```