### Fill array

Use `Array.map()` to map values between `start` (inclusive) and `end` (exclusive) to `value`.
Omit `start` to start at the first element and/or `end` to finish at the last.

```js
const fillArray = (arr, value, start = 0, end = arr.length) => 
  arr.map((v,i) => i>=start && i<end ? value : v);
// fillArray([1,2,3,4],'8',1,3) -> [1,'8','8',4]
```