51 lines
1.1 KiB
JavaScript
51 lines
1.1 KiB
JavaScript
/**
|
|
* Copyright (c) Facebook, Inc. and its affiliates.
|
|
*
|
|
* This source code is licensed under the MIT license found in the
|
|
* LICENSE file in the root directory of this source tree.
|
|
*
|
|
* @format
|
|
* @flow strict
|
|
*/
|
|
|
|
/**
|
|
* Useful method to split an array into groups of the same number of elements.
|
|
* You can use it to generate grids, rows, pages...
|
|
*
|
|
* If the input length is not a multiple of the count, it'll fill the last
|
|
* array with null so you can display a placeholder.
|
|
*
|
|
* Example:
|
|
* groupByEveryN([1, 2, 3, 4, 5], 3)
|
|
* => [[1, 2, 3], [4, 5, null]]
|
|
*
|
|
* groupByEveryN([1, 2, 3], 2).map(elems => {
|
|
* return <Row>{elems.map(elem => <Elem>{elem}</Elem>)}</Row>;
|
|
* })
|
|
*/
|
|
'use strict';
|
|
|
|
function groupByEveryN<T>(array: Array<T>, n: number): Array<Array<?T>> {
|
|
const result = [];
|
|
let temp = [];
|
|
|
|
for (let i = 0; i < array.length; ++i) {
|
|
if (i > 0 && i % n === 0) {
|
|
result.push(temp);
|
|
temp = [];
|
|
}
|
|
temp.push(array[i]);
|
|
}
|
|
|
|
if (temp.length > 0) {
|
|
while (temp.length !== n) {
|
|
temp.push(null);
|
|
}
|
|
result.push(temp);
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
module.exports = groupByEveryN;
|