从goroutine中获取值的最自然的方法是通道。通道是连接并发goroutine的管道。您可以将值从一个goroutine发送到通道，然后将这些值接收到另一个goroutine或在同步函数中。
package main
import (
"fmt"
"io/ioutil"
"log"
"net/http"
"sync"
)
// WaitGroup is used to wait for the program to finish goroutines.
var wg sync.WaitGroup
func responseSize(url string, nums chan int) {
// Schedule the call to WaitGroup's Done to tell goroutine is completed.
defer wg.Done()
response, err := http.Get(url)
if err != nil {
log.Fatal(err)
}
defer response.Body.Close()
body, err := ioutil.ReadAll(response.Body)
if err != nil {
log.Fatal(err)
}
// Send value to the unbuffered channel
nums <- len(body)
}
func main() {
nums := make(chan int) // Declare a unbuffered channel
wg.Add(1)
go responseSize("//www.yfmac.net", nums)
fmt.Println(<-nums) // Read the value from unbuffered channel
wg.Wait()
close(nums) // Closes the channel
}运行上面的程序时，您可能会看到以下输出：
C:\Golang\goroutines\create-simple-goroutine>go run main.go
79655