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30-seconds-of-code/snippets/dropRightWhile.md
Henry 8440492710 just slice arr once
use variable `rightIndex` to make it more efficient, just slice arr once.
2019-05-04 16:32:47 +08:00

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Markdown

### dropRightWhile
Removes elements from the end of an array until the passed function returns `true`. Returns the remaining elements in the array.
Loop through the array, using `Array.prototype.slice()` to drop the last element of the array until the returned value from the function is `true`.
Returns the remaining elements.
```js
const dropRightWhile = (arr, func) => {
let rightIndex = arr.length;
while (rightIndex-- && !func(arr[rightIndex]));
return arr.slice(0, rightIndex + 1);
};
```
```js
dropRightWhile([1, 2, 3, 4], n => n < 3); // [1, 2]
```