https://segmentfault.com/a/1190000008230146
package main
import (
"time"
"log"
)
var a string
func hello() {
time.Sleep(time.Millisecond * 900) // 这里如果sleep 1 秒的话， 执行程序时可能看不到打印的 “hello”
log.Println(a)
}
func main() {
a = "hello\n"
go hello()
time.Sleep(time.Second)
}
原文：https://www.cnblogs.com/oxspirt/p/14763567.html