I am trying to understand channels in Go. I have read that by default sends and receives block until both the sender and receiver are ready. But how do we figure out readyness of sender and receiver.
For example in the following code
package main
import "fmt"
func main() {
ch := make(chan int)
ch <- 1
fmt.Println(<-ch)
}
The program will get stuck on the channel send operation waiting forever for someone to read the value. Even though we have a receive operation in println statement it ends up in a deadlock.
But for the following program
package main
import "fmt"
func main() {
ch := make(chan int)
go func () {
ch <- 1
}()
fmt.Println(<-ch)
}
The integer is passed successfully from go routine to main program. What made this program work? Why second works but first do not? Is go routine causing some difference?