| Leo Repp | 58b9f11 | 2021-11-22 11:57:47 +0100 | [diff] [blame^] | 1 | var baseRandom = require('./_baseRandom'); |
| 2 | |
| 3 | /** |
| 4 | * A specialized version of `_.shuffle` which mutates and sets the size of `array`. |
| 5 | * |
| 6 | * @private |
| 7 | * @param {Array} array The array to shuffle. |
| 8 | * @param {number} [size=array.length] The size of `array`. |
| 9 | * @returns {Array} Returns `array`. |
| 10 | */ |
| 11 | function shuffleSelf(array, size) { |
| 12 | var index = -1, |
| 13 | length = array.length, |
| 14 | lastIndex = length - 1; |
| 15 | |
| 16 | size = size === undefined ? length : size; |
| 17 | while (++index < size) { |
| 18 | var rand = baseRandom(index, lastIndex), |
| 19 | value = array[rand]; |
| 20 | |
| 21 | array[rand] = array[index]; |
| 22 | array[index] = value; |
| 23 | } |
| 24 | array.length = size; |
| 25 | return array; |
| 26 | } |
| 27 | |
| 28 | module.exports = shuffleSelf; |