go 基于select生成随机数

一个很简单小程序：

package main

import (
    "fmt"
)

func main() {
    var rand_number int64

    ch := make(chan int64, 3)

    for i := 0; i < 3; i++ {
        select {
        case ch <- 0:
        case ch <- 1:
        case ch <- 2:
        case ch <- 3:
        case ch <- 4:
        case ch <- 5:
        case ch <- 6:
        case ch <- 7:
        case ch <- 8:
        case ch <- 9:
        }

        rand_number = rand_number*10 + <-ch
    }

    fmt.Println(rand_number)
}