Lodash 源码分析

# shuffle

# Description

创建一个被打乱值的集合。

# Params

array

# Return

Array

# Depend

import copyArray from './.internal/copyArray.js'

copyArray 源码分析

# Code

function shuffle(array) {
  const length = array == null ? 0 : array.length
  if (!length) {
    return []
  }
  let index = -1
  const lastIndex = length - 1
  const result = copyArray(array)
  while (++index < length) {
    const rand = index + Math.floor(Math.random() * (lastIndex - index + 1))
    const value = result[rand]
    result[rand] = result[index]
    result[index] = value
  }
  return result
}

# Analyze

和 sampleSize 的处理逻辑基本一致，通过 rand 和 index 进行值和位置的替换

# Example

console.log(shuffle([1,2,3,4,5,6,7,8])) // [ 3, 8, 2, 7, 5, 6, 1, 4]

← size →