### 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] ```