// - A send to a nil channel blocks forever
var c chan string
c <- "Hello, World!"
// fatal error: all goroutines are asleep - deadlock!

// - A receive from a nil channel blocks forever
var c chan string
fmt.Println(<-c)
// fatal error: all goroutines are asleep - deadlock!

// - A send to a closed channel panics
var c = make(chan string, 1)
c <- "Hello, World!"
close(c)
c <- "Hello, Panic!"
// panic: send on closed channel

// - A receive from a closed channel returns the zero value immediately
var c = make(chan int, 2)
c <- 1
c <- 2
close(c)
for i := 0; i < 3; i++ {
    fmt.Printf("%d ", <-c)
}
// 1 2 0