| 1 | /** |
| 2 | * Provides helper functions for Number handling. |
| 3 | * |
| 4 | * @author Tim Duesterhus |
| 5 | * @copyright 2001-2018 WoltLab GmbH |
| 6 | * @license GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php> |
| 7 | * @module WoltLabSuite/Core/NumberUtil |
| 8 | */ |
| 9 | define([], function() { |
| 10 | "use strict"; |
| 11 | |
| 12 | /** |
| 13 | * @exports WoltLabSuite/Core/NumberUtil |
| 14 | */ |
| 15 | var NumberUtil = { |
| 16 | /** |
| 17 | * Decimal adjustment of a number. |
| 18 | * |
| 19 | * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/round |
| 20 | * @param {Number} value The number. |
| 21 | * @param {Integer} exp The exponent (the 10 logarithm of the adjustment base). |
| 22 | * @returns {Number} The adjusted value. |
| 23 | */ |
| 24 | round: function (value, exp) { |
| 25 | // If the exp is undefined or zero... |
| 26 | if (typeof exp === 'undefined' || +exp === 0) { |
| 27 | return Math.round(value); |
| 28 | } |
| 29 | value = +value; |
| 30 | exp = +exp; |
| 31 | |
| 32 | // If the value is not a number or the exp is not an integer... |
| 33 | if (isNaN(value) || !(typeof exp === 'number' && exp % 1 === 0)) { |
| 34 | return NaN; |
| 35 | } |
| 36 | |
| 37 | // Shift |
| 38 | value = value.toString().split('e'); |
| 39 | value = Math.round(+(value[0] + 'e' + (value[1] ? (+value[1] - exp) : -exp))); |
| 40 | |
| 41 | // Shift back |
| 42 | value = value.toString().split('e'); |
| 43 | return +(value[0] + 'e' + (value[1] ? (+value[1] + exp) : exp)); |
| 44 | } |
| 45 | }; |
| 46 | |
| 47 | return NumberUtil; |
| 48 | }); |