日本免费高清视频-国产福利视频导航-黄色在线播放国产-天天操天天操天天操天天操|www.shdianci.com

學(xué)無先后，達(dá)者為師

網(wǎng)站首頁 編程語言 正文

golang?數(shù)組隨機(jī)排序的實現(xiàn)_Golang

作者：董洪臣 ? 更新時間： 2022-03-17 編程語言

前言

目前接到一個推薦數(shù)據(jù)的需求，需要將數(shù)據(jù)庫中獲取到的數(shù)據(jù)進(jìn)行隨機(jī)排序后返回給用戶。考慮了一下，有兩種使用方式，一種是通過數(shù)據(jù)庫 order by rand() ，還有一種就是本文需要使用到的代碼處理

具體實現(xiàn)步驟如下

1.引入庫

代碼如下：

import (
 "fmt"
 "math/rand"
 "time"
)

2.組裝數(shù)據(jù)并排序(方案一)

代碼如下：

type CategoryEntity struct {
 GrouponId     int64  //團(tuán)ID
 MerchandiseId int64  //商品ID
 CategoryId    int64  //分類ID
 CategoryTitle string //分類名稱
}

func main() {
 data := make([]CategoryEntity, 10)
 data[0] = CategoryEntity{GrouponId: 0, MerchandiseId: 1117891, CategoryId: 726, CategoryTitle: "蔬菜"}
 data[1] = CategoryEntity{GrouponId: 1, MerchandiseId: 1110162, CategoryId: 1505, CategoryTitle: "調(diào)料調(diào)味"}
 data[2] = CategoryEntity{GrouponId: 2, MerchandiseId: 1117822, CategoryId: 746, CategoryTitle: "水果"}
 data[3] = CategoryEntity{GrouponId: 3, MerchandiseId: 1115770, CategoryId: 1408, CategoryTitle: "個人護(hù)理"}
 data[4] = CategoryEntity{GrouponId: 4, MerchandiseId: 1116528, CategoryId: 732, CategoryTitle: "肉"}
 data[5] = CategoryEntity{GrouponId: 5, MerchandiseId: 1116526, CategoryId: 727, CategoryTitle: "休閑食品"}
 data[6] = CategoryEntity{GrouponId: 6, MerchandiseId: 1117188, CategoryId: 728, CategoryTitle: "糧油調(diào)味"}
 data[7] = CategoryEntity{GrouponId: 7, MerchandiseId: 1117379, CategoryId: 726, CategoryTitle: "蔬菜"}
 data[8] = CategoryEntity{GrouponId: 8, MerchandiseId: 1118166, CategoryId: 1005, CategoryTitle: "居家百貨"}
 data[9] = CategoryEntity{GrouponId: 9, MerchandiseId: 1117377, CategoryId: 746, CategoryTitle: "水果"}

 fmt.Println("隨機(jī)前:", data)
 //如果不使用rand.Seed(seed int64)，每次運(yùn)行，得到的隨機(jī)數(shù)會一樣
 rand.Seed(time.Now().Unix())
 //采用rand.Shuffle，將切片隨機(jī)化處理后返回
 rand.Shuffle(len(data), func(i, j int) { data[i], data[j] = data[j], data[i] })
 fmt.Println("隨機(jī)后:", data)
}

3.組裝數(shù)據(jù)并排序(方案二)

代碼如下：

type CategoryEntity struct {
 GrouponId     int64  //團(tuán)ID
 MerchandiseId int64  //商品ID
 CategoryId    int64  //分類ID
 CategoryTitle string //分類名稱
}

func main() {
 data := make([]CategoryEntity, 10)
 data[0] = CategoryEntity{GrouponId: 0, MerchandiseId: 1117891, CategoryId: 726, CategoryTitle: "蔬菜"}
 data[1] = CategoryEntity{GrouponId: 1, MerchandiseId: 1110162, CategoryId: 1505, CategoryTitle: "調(diào)料調(diào)味"}
 data[2] = CategoryEntity{GrouponId: 2, MerchandiseId: 1117822, CategoryId: 746, CategoryTitle: "水果"}
 data[3] = CategoryEntity{GrouponId: 3, MerchandiseId: 1115770, CategoryId: 1408, CategoryTitle: "個人護(hù)理"}
 data[4] = CategoryEntity{GrouponId: 4, MerchandiseId: 1116528, CategoryId: 732, CategoryTitle: "肉"}
 data[5] = CategoryEntity{GrouponId: 5, MerchandiseId: 1116526, CategoryId: 727, CategoryTitle: "休閑食品"}
 data[6] = CategoryEntity{GrouponId: 6, MerchandiseId: 1117188, CategoryId: 728, CategoryTitle: "糧油調(diào)味"}
 data[7] = CategoryEntity{GrouponId: 7, MerchandiseId: 1117379, CategoryId: 726, CategoryTitle: "蔬菜"}
 data[8] = CategoryEntity{GrouponId: 8, MerchandiseId: 1118166, CategoryId: 1005, CategoryTitle: "居家百貨"}
 data[9] = CategoryEntity{GrouponId: 9, MerchandiseId: 1117377, CategoryId: 746, CategoryTitle: "水果"}

 fmt.Println("隨機(jī)前:", data)
 //如果不使用rand.Seed(seed int64)，每次運(yùn)行，得到的隨機(jī)數(shù)會一樣
 rand.Seed(time.Now().Unix())
 length := len(data)
 for i := 0; i < length; i++ {
  exchange(data, rand.Intn(length), i)
 }

 fmt.Println("隨機(jī)后:", data)
}

// 交換數(shù)據(jù)
func exchange(data []CategoryEntity, i, j int) {
 data[i], data[j] = data[j], data[i]
}

總結(jié)

整體比較簡單，但是需要注意的有兩點：

1：golang中 rand的使用方式，如果不使用rand.Seed(seed int64)，每次運(yùn)行，得到的隨機(jī)數(shù)會一樣

2：方案一種采用rand.Shuffle+匿名函數(shù)，將切片隨機(jī)化處理后返回。

3：方案二使用golang特有的數(shù)組交換方式：

func exchange(data []CategoryEntity, i, j int) {
 data[i], data[j] = data[j], data[i]
}

原文鏈接：https://blog.csdn.net/dong945221578/article/details/116067051

欄目分類
最近更新