go - 在自定义范围内生成随机数

Question

我的 go 脚本以“localhost:8080/1”开头，带有previous 和next 链接我需要添加Random 链接具有自定义范围，我可以像这样更改:

• 小数字，例如 100 到 200 "localhost:8080/100 - 200"和
• 甚至是大数字，例如:“16567684686592643791596485465456223131545455682945955”

所以:

// Get next and previous page numbers

previous := new(big.Int).Sub(page, one)
next := new(big.Int).Add(page, one)
random :=????

Answer 1

您需要使用包 crypto.rand Int()函数，它确实支持 big.Int(与 math.rand package 相对)

参见 this article (及其 playground example ):

package main

import (
    "fmt"
    "math/big"
    "crypto/rand"
)

func main() {
    var prime1, _ = new(big.Int).SetString("21888242871839275222246405745257275088548364400416034343698204186575808495617", 10)
    // Generate random numbers in range [0..prime1]
    // Ignore error values
    // Don't use this code to generate secret keys that protect important stuff!
    x, _ := rand.Int(rand.Reader, prime1)
    y, _ := rand.Int(rand.Reader, prime1)
    fmt.Printf("x: %v\n", x)
    fmt.Printf("y: %v\n", y)

}