小白提问：go 通道发送操作的疑惑

代码如下： ``` package main import "fmt" func main() { ch1 := make(chan int, 1) go func() { for i := 0; i < 10; i++ { fmt.Printf("Sender: sending element %v ... \n", i) ch1 <- i } fmt.Println("Sender: close the channel") close(ch1) }() for { elem, ok := <-ch1 if !ok { fmt.Println("Receiver: closed the channel") break } fmt.Printf("Receiver: received an element%v \n", elem) } fmt.Println("End!") } ``` 输出结果： ``` Sender: sending element 0 ... Sender: sending element 1 ... Sender: sending element 2 ... Receiver: received an element0 Receiver: received an element1 Receiver: received an element2 Sender: sending element 3 ... Sender: sending element 4 ... Sender: sending element 5 ... Receiver: received an element3 Receiver: received an element4 Receiver: received an element5 Sender: sending element 6 ... Sender: sending element 7 ... Sender: sending element 8 ... Receiver: received an element6 Receiver: received an element7 Receiver: received an element8 Sender: sending element 9 ... Sender: close the channel Receiver: received an element9 Receiver: closed the channel End! ``` 我的问题是为什么一次能发3个元素，但通道的缓冲区只设置为了1啊，是因为go func(){}()开启了3个goroutine吗？ 麻烦解答一下，谢谢