package main

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

func main() {
    //设置随机数种子
    rand.Seed(time.Now().UnixNano())
    var captcha string
    for i := 0; i < 6; i++ {
        //产生0到9的整数
        num = rand.Intn(10)
        //将整数转为字符串
        captcha += strconv.Itoa(num)
    }
    fmt.Println(captcha)
}