package main

import (
    "fmt"
    "time"
)

func main() {
    c1 := make(chan string)
    c2 := make(chan string)

    go func() {
        time.Sleep(time.Second * 1)
        c1 <- "one"
    }()

    go func() {
        time.Sleep(time.Second * 2)
        c2 <- "two"
    }()

    for i := 0; i < 2; i++ {
        //通道選擇器同時等待多個通道操作。
        select {
        //哪個通道獲得資料就執行哪個case，select結束
        case msg1 := <-c1:
            fmt.Println(msg1)
        case msg2 := <-c2:
            fmt.Println(msg2)
        }
    }
}