projects / GitHub / WoltLab / WCF.git / blame
| Commit | Line | Data |
|---|---|---|
| ad35859f TD |
1 | /** |
| 2 | * Provides helper functions for Number handling. | |
| 3 | * | |
| 4 | * @author Tim Duesterhus | |
| 5 | * @copyright 2001-2015 WoltLab GmbH | |
| 6 | * @license GNU Lesser General Public License <http://opensource.org/licenses/lgpl-license.php> | |
| 7 | * @module WoltLab/WCF/NumberUtil | |
| 8 | */ | |
| 9 | define([], function() { | |
| 10 | "use strict"; | |
| 11 | ||
| 12 | /** | |
| 13 | * @constructor | |
| 14 | */ | |
| 15 | function NumberUtil() { }; | |
| 16 | NumberUtil.prototype = { | |
| 17 | /** | |
| 18 | * Decimal adjustment of a number. | |
| 19 | * | |
| 20 | * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/round | |
| 21 | * @param {Number} value The number. | |
| 22 | * @param {Integer} exp The exponent (the 10 logarithm of the adjustment base). | |
| 23 | * @returns {Number} The adjusted value. | |
| 24 | */ | |
| 25 | round: function (value, exp) { | |
| 26 | // If the exp is undefined or zero... | |
| 27 | if (typeof exp === 'undefined' || +exp === 0) { | |
| 28 | return Math.round(value); | |
| 29 | } | |
| 30 | value = +value; | |
| 31 | exp = +exp; | |
| 32 | ||
| 33 | // If the value is not a number or the exp is not an integer... | |
| 34 | if (isNaN(value) || !(typeof exp === 'number' && exp % 1 === 0)) { | |
| 35 | return NaN; | |
| 36 | } | |
| 37 | ||
| 38 | // Shift | |
| 39 | value = value.toString().split('e'); | |
| 40 | value = Math.round(+(value[0] + 'e' + (value[1] ? (+value[1] - exp) : -exp))); | |
| 41 | ||
| 42 | // Shift back | |
| 43 | value = value.toString().split('e'); | |
| 44 | return +(value[0] + 'e' + (value[1] ? (+value[1] + exp) : exp)); | |
| 45 | } | |
| 46 | }; | |
| 47 | ||
| 48 | return new NumberUtil(); | |
| 49 | }); |