func Worker(id int, c chan int) {
	//for n := range c {
	for {
		fmt.Printf("Worker %d received %d
", id, <-c)
	}
}

// createworker, return type chan
func CreateWorker(id int) chan<- int {
	c := make(chan int)
	go Worker(id, c)
	return c
}

func ChanDemo() {
	var channels [10]chan<- int
	for i := 0; i < 10; i++ {
		channels[i] = CreateWorker(i) 
	}

	for i := 0; i < 10; i++ {
		channels[i] <- 'a' + i 
	}

	time.Sleep(time.Millisecond)
}

// buffer channel
func BufferChan() {
	c := make(chan int, 4)
	go Worker(1, c)
	c <- 1
	c <- 2
	c <- 3
	c <- 4
	c <- 5
	close(c)
	//time.Sleep(time.Millisecond)
}

func main() {
	// ChanDemo()
	BufferChan()
}

代码如上，在使用缓存channel时，发现连续按运行，有时候可以打印出5行来，有时候打印只有一行，有时候完全打印不出来。这是什么原因呢？go的版本是1.13.4