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- /**
- * 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;
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