# Golang: math/rand 和 crypto/rand 区别

## 1. 前言

### 原文地址

`math/rand`软件包可以用于简单的游戏，但不能用于真正的随机性。

• `math/rand`: 伪随机数生成器
• `crypto/rand`: 加密安全的随机数生成器

Rob Pike的代码

``````package main

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

func main() {
c := fanIn(boring("Joe"), boring("Ann"))
for i := 0; i < 10; i++ {
fmt.Println(<-c)
}
fmt.Println("You're both boring; I'm leaving.")
}

func boring(msg string) <-chan string {
c := make(chan string)
go func() {
for i := 0; ; i++ {
c <- fmt.Sprintf("%s %d", msg, i)
time.Sleep(time.Duration(rand.Intn(1e3)) * time.Millisecond)
}
}()
return c
}

// FAN IN
func fanIn(input1, input2 <-chan string) <-chan string {
c := make(chan string)
go func() {
for {
c <- <-input1
}
}()
go func() {
for {
c <- <-input2
}
}()
return c
}

``````

## 2. Math/rand 伪随机数生成器

``````package main

import (
"fmt"
"math/rand"
"time"
)
func init(){
rand.Seed(time.Now().UTC().UnixNano())
}

func main() {

// launches 2 generators and the fanIn collector function
c := fanIn(genrt(), genrt())
for i := 0; i < 10000; i++ {
fmt.Println(<-c)
}
}

func fanIn(a <-chan int, b <-chan int) <-chan string {
c := make(chan string)
// launch collector from a to channel
go func() {
var count int
for {
count += <-a
c <- fmt.Sprintf("Tally of A is: %d", count)
}
}()
// launch collector from b to channel
go func() {
var count int
for {
count += <-b
c <- fmt.Sprintf("Tally of B is: %d", count)
}
}()

return c
}

func genrt() <-chan int {
c := make(chan int)
// launch generator of Dice rolls
go func() {
for i := 0; ; i++ {
c <- rand.Intn(6) + 1
time.Sleep(time.Duration(500 * time.Millisecond))
}
}()
return c
}

``````

``````...
Tally of B is: 17656
Tally of A is: 17438
Tally of A is: 17440
Tally of B is: 17659
Tally of B is: 17660
Tally of A is: 17445
``````

## 3. Crypto/rand 加密安全的随机数生成器

``````package main
import (
"crypto/rand"
"fmt"
"math/big"
"time"
)

func main() {

// launches 2 generatores and the fanIn collector function
c := fanIn(genrt(), genrt())
for i := 0; i < 10000; i++ {
fmt.Println(<-c)
}
}

func fanIn(a <-chan int, b <-chan int) <-chan string {
c := make(chan string)
// launch collector from a to channel
go func() {
var count int
for {
count += <-a
c <- fmt.Sprintf("Tally of A is: %d", count)
}
}()
// launch collector from b to channel
go func() {
var count int
for {
count += <-b
c <- fmt.Sprintf("Tally of B is: %d", count)
}
}()

return c
}

func genrt() <-chan int {
c := make(chan int)
// launch generator of Dice rolls
go func() {
for i := 0; ; i++ {
if err != nil {
fmt.Println(err)
}
c <- int(dice.Int64()) + 1
time.Sleep(time.Duration(1 * time.Millisecond))
}
}()
return c
}

``````

``````...
Tally of B is: 17496
Tally of A is: 17570
Tally of A is: 17574
Tally of B is: 17500
Tally of B is: 17505
Tally of A is: 17576``````

##### golang后端
Go语言后端技术分享,希望 [链接]的内容对大家的学习或者工作能带来一定的帮助,如果有疑问大家可以留言交...

mojotv.cn

447 声望
33 粉丝
0 条评论