package tools

import (
	"math/rand"
	"time"
)

func init() {
	// 随机数种子
	rand.Seed(time.Now().UnixNano())
}

// RandStr 生成随机数
func RandStr(n int, str ...string) string {
	s := "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"
	if len(str) > 0 {
		s = str[0]
	}
	res := ""
	for i := 0; i < n; i++ {
		res += string(s[rand.Intn(len(s))])
	}
	return res
}